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The high-power piezoelectric properties of MnO2-doped 〈001〉 and 〈111〉 textured 0.24PIN–0.42PMN–0.34PT ceramics are compared to understand the orientation dependence.

In this work, [001] textured Sm0.025Pb0.9625(Mg1/3Nb2/3)0.74Ti0.26O3 (Sm-PMN-26PT) ceramics were synthesized by the templated grain growth method. The dielectric, piezoelectric, and electromechanical properties of untextured and textured ceramics are systematically studied. A high texture degree of 99% was obtained using 1% volume fraction of the BaTiO3 (BT) template. The textured ceramics exhibit an excellent piezoelectric coefficient d33 of 1882 pC/N at room temperature, and an extremely high d33* of 2510 pm/V is obtained. The dielectric, ferroelectric, and strain characteristics reveal that the improvement of piezoelectric properties of textured ceramics comes from the increase of dielectric constant ε33 and electrostriction coefficient Q33. Both the intrinsic response of the domain and the external contribution of the domain wall are enhanced in [001] textured ceramics, which may be the microscopic mechanism of increased piezoelectric activity. The Sm-PMN-26PT textured ceramics exhibit excellent piezoelectric properties, which are very promising for using at room temperature.

Piezoelectric materials should simultaneously possess the soft properties (high piezoelectric coefficient, d

Driven by an ever-growing demand for environmentally benign cooling systems, the past decade has witnessed the booming development in the field of electrocaloric (EC) cooling technology, which is considered as a promising solid-state cooling approach. Multilayer ceramic chip capacitors (MLCCs) represent the optimum structure for EC cooling elements because of large breakdown strengths, low driving voltages, and high macroscopic volumes of active EC materials. However, fundamental relationships between the geometric parameters of MLCCs and the EC coefficient are less understood. In this study, 0.92Pb(Mg1/3Nb2/3)O3-0.08PbTiO3 (PMN-PT) MLCCs with controlled configurations, such as active/inactive layer thickness, number of layers, and active volume ratio, were fabricated, and their EC performance was evaluated. The electric properties of the MLCCs are confirmed to be closely related to the geometric structure, which influences not only the heat flow but also the internal stress, resulting in the variability of EC performance and reliability/breakdown strength. The internal stress arises due to the residual thermal stress originating from the densification-related shrinkage, thermal expansion mismatch during the sintering, and clamping stress arising from the inactive area due to the large strain from the active area under a high electric field. The geometric structure-based stress distribution and the magnitude of stress on the active layers in MLCCs were determined by finite element modeling (FEM) and correlated with the experimental EC coefficients. The results reveal that a low inactive volume percentage is beneficial toward increasing the breakdown field and enhancement of EC performance because of reduced clamping stress on active EC material.

Control of magnetic permeability through electric field in magnetoelectric materials promises to create novel voltage tunable inductors (VTIs). VTIs synthesized using co-fired ceramic processing exhibit many advantages over traditional epoxy bonding method, but the internal residual stress in co-fired VTIs resulting from thermal expansion mismatch hinders a full exploitation of the tunability of permeability. To find the optimal condition for high tunability of co-fired VTIs, domain-level phase field modeling and computer simulation are employed to study co-fired magnetoelectric composites comprising NiZn ferrite and PZT. Two key factors important toward increasing the inductor tunability are systematically investigated: intrinsic magnetocrystalline anisotropy of the ferrite material and internal residual stress caused by the co-firing process. The simulations indicate that in order to achieve a large tunability, the tuned permeability should be confined within the linear region of the reciprocal of susceptibility and stress. Additionally, both magnetocrystalline anisotropy and residual stress should be as small as possible. These results provide a design strategy for realizing high-tunability co-fired VTIs.

Relaxor ferroelectrics (RFEs) are being actively investigated for energy storage applications due to their large electric-field-induced polarization with slim hysteresis and fast energy charging-discharging capability. Here, we report a nanograin engineering approach based upon high kinetic energy deposition for artificially inducing the RFE behavior in a normal ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT) and simultaneously enhancing the dielectric breakdown strength (EDBS) and polarization. Artificially engineered polycrystalline relaxor PZT films with 4 µm thickness exhibited an exceptional EDBS of 540 MV/m and reduced hysteresis with large unsaturated polarization (103.6 µC/cm2), resulting in an ultrahigh energy storage density of 124 J/cm3 and a power density of 64.5 MW/cm3. This fundamental microstructure-based design approach overcomes the limitations imposed by composition and provides a feasible pathway for designing high-performance energy storage materials, where high EDBS, reduced hysteretic behavior, and enhanced polarization are required.

Lower-dimensional quasi-two-dimensional (quasi-2D) halide perovskites have emerged as promising building blocks for multiple optoelectronic applications due to their superior photophysical properties. Recently, there has been a research focus on the terrace edge states (TES) in quasi-2D perovskites, which are thought to provide hypothetical highways to transport the excited states and thus give a new insight into boosting relevant device performance. Nevertheless, there is neither direct evidence of the electronic facets nor an in-depth understanding of these newly observed nontrivial TES. Here, we are the first to directly visualize the highly charged concentrated TES by means of a charge gradient microscopy (CGM) technique and elucidate the nature of TES through a combination of microscopic characterizations, including high-resolution transmission electron microscopy, Kelvin probe force microscopy and confocal fluorescence microscopy coupled with a first-principles density functional theory (DFT) calculation. It is shown that TES of quasi-2D perovskites are highly conductive (in distinct contrast to the insulating flat terrace region) and display a high Fermi-level and small forbidden bandwidth, which is attributed to the unique electron orbitals of the Pb atoms at the terrace edges. This distinctive conductivity of TES is of great importance in distinguishing them from bulk physical properties and inspiring novel nanoscale electronic applications, such as tip-based data storage and triboelectric nanogenerators.

The determination of complex elastic, piezoelectric, and dielectric coefficients of piezoelectric ceramics is important for precision engineering devices. Here, a novel method for determining the optimal material coefficients is presented. This method minimizes the average relative error in the values of conductance, susceptance, resistance, and reactance obtained from the 1-D model in the IEEE Standard (ANSI/IEEE Std 176-1987) and the experimental measurements of the first and second radial modes. Poisson’s ratio is assumed to be a complex number in addition to the elastic, piezoelectric, and dielectric coefficients in the present method. The global minimum of the average relative error is found by searching the minimum among all local minima of the average relative error, which are obtained with the Levenberg–Marquardt modification of Newton’s method from randomly chosen initial conditions. The optimal material coefficients of an APC 850 disk and an APC 855 disk are calculated with this method. The uncertainties in the optimal material coefficients are evaluated by calculating the minimum average relative error when the real or imaginary part of each coefficient is prescribed.

Electromechanical coupling factor, k, of piezoelectric materials determines the conversion efficiency of mechanical to electrical energy or electrical to mechanical energy. Here, we provide an fundamental approach to design piezoelectric materials that provide near-ideal magnitude of k, via exploiting the electrocrystalline anisotropy through fabrication of grain-oriented or textured ceramics. Coupled phase field simulation and experimental investigation on textured Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3 ceramics illustrate that k can reach same magnitude as that for a single crystal, far beyond the average value of traditional ceramics. To provide atomistic-scale understanding of our approach, we employ a theoretical model to determine the physical origin of k in perovskite ferroelectrics and find that strong covalent bonding between B-site cation and oxygen via d-p hybridization contributes most towards the magnitude of k. This demonstration of near-ideal k value in textured ceramics will have tremendous impact on design of ultra-wide bandwidth, high efficiency, high power density, and high stability piezoelectric devices.

Environmentally friendly NaNbO3 capacitors have a great potential for applications in pulsed-discharge and power conditioning electronic systems because of their AFE-like hysteresis behavior, high saturation polarization and low mass. Here, we demonstrate (0.96 − x)NaNbO3–0.04CaZrO3–xBi0.5Na0.5TiO3 (abbreviated as NN-CZ-xBNT) capacitors with high energy storage density (Wrec) and efficiency (η). The performances of capacitors were tuned by the composition induced relaxor behavior and grain refinement which resulted in reduction of hysteresis and increase in the breakdown strength (BDS). Two-step sintering is found to be effective for reducing the grain size of MLCCs to 3 μm, which is 86% smaller as compared to grain size obtained by conventional solid-state sintering (22 μm). Small grain size significantly reduces the leakage current and losses and increases the BDS, yielding excellent Wrec = 3.7 J cm−3 and η = 82.1% in the NN-0.04CZ-0.16BNT multilayered capacitors. Results provide a systematic strategy for enhancing the energy storage density and efficiency of dielectric capacitors through the combination of dielectric relaxation and grain size refinement.

In the emerging era of Internet of Things (IoT), power sources for wireless sensor nodes in conjunction with efficient and secure wireless data transfer are required. Energy harvesting technologies are promising solution toward meeting the requirements for sustainable power sources for the IoT. In this review, we focus on approaches for harvesting stray vibrations and magnetic field due to their abundance in the environment. Piezoelectric materials and piezoelectric–magnetostrictive [magnetoelectric (ME)] composites can be used to harvest vibration and magnetic field, respectively. Currently, such harvesters use modified lead zirconate titanate (or lead-based) piezoelectric materials and ME composites. However, environmental concerns and government regulations require the development of a suitable lead-free replacement for lead-based piezoelectric materials. In the past decade, several lead-free piezoelectric compositions have been developed and demonstrated with promising piezoelectric response. This paper reviews the significant results reported on lead-free piezoelectric materials with respect to high-density energy harvesting, covering novel processing techniques for improving the piezoelectric response and temperature stability. The review of the state-of-the-art studies on vibration and magnetic field harvesting is provided and the results are used to discuss various strategies for designing high-performance energy harvesting devices.

The reliability of piezoelectric transformers (PTs) is dependent upon the quality of fabrication technique as any heterogeneity, prestress, or misalignment can lead to spurious response. In this paper, unipoled multilayer PTs were investigated focusing on high-power composition and co-firing profile in order to provide low-temperature synthesized high-quality device measured in terms of efficiency and power density. The addition of 0.2 wt% CuO into Pb0.98Sr0.02(Mg1/3Nb2/3)0.06(Mn1/3Nb2/3)0.06(Zr0.48Ti0.52)0.88O3 (PMMnN-PZT) reduces the co-firing temperature from 1240 °C to 930 °C, which allows the use of Ag/Pd inner electrode instead of noble Pt inner electrode. Low-temperature synthesized material was found to exhibit excellent piezoelectric properties ( $Q_{m} = 1300$ , $k_{p}= 0.47$ , $\tan \delta = 0.4$ %, $d_{33} = 218$ pC/N, and $T_{c}= 325$ °C). The performance of the PT co-fired with Ag/Pd electrode at 930 °C was similar to that co-fired at 1240 °C with Pt electrode (25% reduction in sintering temperature). Both high- and low-temperature synthesized PTs demonstrated 5-W output power with >90% efficiency and 11.5 W/cm3 power density.

Control of magnetic permeability through voltage promises to create novel electronic devices, such as voltage tunable inductors. The relationship between the structure and property of voltage tunable inductors comprising of magnetoelectric Metglas/PZT composites and the underlying domain-level mechanisms are investigated using theoretical analysis, computer simulation, and complementary experiments. A theoretical model is developed to analyze the roles of material anisotropy, inductor shape, and stress in controlling the Metglas permeability and its tunability. The analysis reveals key roles played by stress-induced anisotropy and the resultant ground magnetization state, and predicts two stress-dependent regimes of inductance tunability. The theory is validated using systematic experiments. The experimental results are used to determine the material and physical parameters. To further elucidate the underlying domain-level mechanisms responsible for controlling the behavior of voltage tunable inductor, phase field modeling is employed to simulate domain microstructures and magnetic permeability of Metglas/PZT composites under varying voltage. The computational results confirm the two regimes of inductance tunability and the controlling role of stress-induced anisotropy. The findings suggest engineering of internal bias stress as an effective means to optimize the inductance tunability of magnetoelectric Metglas/PZT composites.

The toxicity of lead present in organohalide perovskites and the hazardous solvent system used for their synthesis hinders the deployment of perovskite solar cells (PSCs). Here, we report an environmentally friendly route for synthesis of bismuth based lead-free (CH3NH3)3Bi2I9 perovskites that utilize ethanol as the solvent. Using this method, dense and homogeneous microstructure was obtained, compared the porous rough microstructure obtained by DMF solution. Thus, the photovoltaic performance was enhanced and open voltage as high as 0.84 V can be obtained.

Owing to their high conversion efficiency and potentially cost-effective manufacturing, organic–inorganic lead halide perovskite solar cells (PSCs) have been dominant photovoltaic research topic in this decade. The photovoltaic performance of PSCs is highly dependent upon the quality of perovskite layer. In order to advance the deployment of PSCs, fabrication of high-quality perovskite film using a facile and sustainable process is essential. This study provides significant breakthrough in this direction. A novel fabrication process is demonstrated that allows slicing of 2D layers from single crystals and restacking them to fabricate high-quality perovskite film. The discovery that CH3NH2 can slice the 3D CH3NH3PbI3 perovskite crystal into 2D layered perovskite intermediates via intercalation process opens a new pathway for pursuing synthesis of a variety of photovoltaic materials. The 2D layered intermediate shows high solubility in acetonitrile (ACN) solvent, which is considered as a replacement for N, N-dimethylformamide (DMF) in order to enable sustainable processing. This solvent system enables fabrication of high-quality perovskite layer by one-step synthesis method. Based on this cost-effective sustainable synthesis approach, low temperature processed PSC was found to match the performance of PSC synthesized using high temperature process.

The transition of autonomous vehicles into fleets requires an advanced control system design that relies on continuous feedback from the tires. Smart tires enable continuous monitoring of dynamic parameters by combining strain sensing with traditional tire functions. Here, we provide breakthrough in this direction by demonstrating tire-integrated system that combines direct mask-less 3D printed strain gauges, flexible piezoelectric energy harvester for powering the sensors and secure wireless data transfer electronics, and machine learning for predictive data analysis. Ink of graphene based material was designed to directly print strain sensor for measuring tire-road interactions under varying driving speeds, normal load, and tire pressure. A secure wireless data transfer hardware powered by a piezoelectric patch is implemented to demonstrate self-powered sensing and wireless communication capability. Combined, this study significantly advances the design and fabrication of cost-effective smart tires by demonstrating practical self-powered wireless strain sensing capability., Designing efficient sensors for smart tires for autonomous vehicles remains a challenge. Here, the authors present a tire-integrated system that combines direct mask-less 3D printed strain gauges, flexible piezoelectric energy harvester for powering the sensors and secure wireless data transfer electronics, and machine learning for predictive data analysis.

The PICO Collaboration wishes to thank SNOLAB and its staff for support through underground space, logistical and technical services. SNOLAB operations are supported by the Canada Foundation for Innovation and the Province of Ontario Ministry of Research and Innovation, with underground access provided by Vale at the Creighton mine site. We wish to acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI) for funding. We acknowledge the support from National Science Foundation (NSF) (Grants No. 0919526, No. 1506337, No. 1242637, No. 1205987, and No. 1806722). We acknowledge that this work is supported by the U.S. Department of Energy (DOE) Office of Science, Office of High Energy Physics (under Award No. DE-SC-0012161), by DGAPA-UNAM (PAPIIT No. IA100118) and Consejo Nacional de Ciencia y Tecnologia (CONACyT, M?exico, Grants No. 252167 and No. A1-S-8960), by the Department of Atomic Energy (DAE), Government of India, under the Centre for AstroParticle Physics II project (CAPP-II) at the Saha Institute of Nuclear Physics (SINP), European Regional Development Fund?Project ?Engineering Applications of Microworld Physics? (Project No. CZ.02.1.01/0.0/0.0/ 16_019/0000766), and the Spanish Ministerio de Ciencia, Innovacion y Universidades (Red Consolider MultiDark, Grant No. FPA2017-90566-REDC). This work is partially supported by the Kavli Institute for Cosmological Physics at the University of Chicago through NSF Grant No. 1125897, and an endowment from the Kavli Foundation and its founder Fred Kavli. We also wish to acknowledge the support from Fermi National Accelerator Laboratory under Contract No. DE-AC02-07CH11359, and Pacific Northwest National Laboratory, which is operated by Battelle for the U.S. Department of Energy under Contract No. DE-AC05- 76RL01830. We also thank Compute Canada [75] and the Center for Advanced Computing, ACENET, Calcul Qu?ebec, Compute Ontario, and WestGrid for computational support.

The PICO Collaboration wishes to thank SNOLAB and its staff for support through underground space, logistical and technical services. SNOLAB operations are supported by the Canada Foundation for Innovation and the Province of Ontario Ministry of Research and Innovation, with underground access provided by Vale at the Creighton mine site. We are grateful to Genevieve Belanger and Alexander Pukhov of the Universit e de Savoie for their useful correspondence regarding the interpretation of PICO results. We wish to acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI) for funding. We acknowledge the support from the National Science Foundation (NSF) (Grants No. 0919526, No. 1506337, No. 1242637, No. 1205987, and No. 1806722). We acknowledge that this work is supported by the U.S. Department of Energy (DOE) Office of Science, Office of High Energy Physics (under Award No. DE-SC-0012161), by the DOE Office of Science Graduate Student Research (SCGSR) award, by DGAPA-UNAM (PAPIIT No. IA100118) and Consejo Nacional de Ciencia y Tecnologia (CONACyT, Mexico, Grants No. 252167 and No. A1-S-8960), by the Department of Atomic Energy (DAE), Government of India, under the Centre for AstroParticle Physics II project (CAPP-II) at the Saha Institute of Nuclear Physics (SINP), European Regional Development FundProject "Engineering applications of microworld physics" (No. CZ. 02.1.01/0.0/0.0/16_019/0000766), and the Spanish (Ministry of Science, Innovation and Universities) Ministerio de Ciencia, Innovacion y Universidades (Red Consolider MultiDark, FPA2017-90566-REDC). This work is partially supported by the Kavli Institute for Cosmological Physics at the University of Chicago through NSF Grant No. 1125897, and an endowment from the Kavli Foundation and its founder Fred Kavli. We also wish to acknowledge the support from Fermi National Accelerator Laboratory under Contract No. DE-AC02-07CH11359, and from Pacific Northwest National Laboratory, which is operated by Battelle for the U.S. Department of Energy under Contract No. DE-AC05-76RL01830. We also thank Compute Canada (www.computecanada.ca) and the Centre for Advanced Computing, ACENET, Calcul Quebec, Compute Ontario and WestGrid for computational support.

This study demonstrates the integrated approach based upon texturing and acceptor doping for realizing a high-power piezoelectric ceramic with combined soft and hard properties. The textured Mn-doped 0.24 Pb(In1/2Nb1/2)O3-0.42 Pb(Mg1/3Nb2/3)O3-0.34 PbTiO3 (PIN-PMN-PT) ceramic exhibits enhanced piezoelectric coefficient d33 and electromechanical coupling factor k31 in comparison with random counterpart. This enhanced piezoelectric response originates from the combined intrinsic high piezoelectric properties of -oriented grains, and reduced energy barrier for polarization rotation in textured ceramics. The BaTiO3 (BT) template in textured ceramics increases the tetragonality degree which results in improved coercive field Ec but decreased mechanical quality factor Qm in comparison with random counterpart. The decreased Qm values of textured ceramics are related to the crystallographic dependence of Qm and the enhanced domain mobility due to the existence of small size domains. The textured ceramic with 2 vol.% BT content exhibited an excellent combination of soft and hard piezoelectric properties, measured to be: d33 = 517 pC/N, Qm = 1147, Ec = 10.0 kV/cm, and tan δ = 0.49%, which is highly promising for high power piezoelectric applications.

One of the critical problems in fabrication of flexible perovskite modules and resolving their reliability issue remains the necessity to utilize high temperature annealing for synthesis of perovskite and electron transport layers. Here, we provide a breakthrough in addressing these challenges by demonstrating low temperature synthesis of both of these layers. HC(NH)2PbI3 (commonly known as FAPbI3) has two polymorphs, a high temperature-stable black FAPbI3 perovskite-type pseudocubic polymorph (α-phase) and a low temperature-stable yellow non-perovskite hexagonal polymorph (δ-phase). In order to understand the crystallization kinetics of the FAPbI3 black polymorph, a PbI2-NMP complex is fabricated via solvent intercalation between the adjacent I-Pb-I layers. Utilizing structural, electrical, and thermal analyses, the connection between solvent intercalation and the crystallization of the FAPbI3 black polymorph is established. It is found that the solvent intercalation in the PbI2 crystal causes lattice st...

Crystallographic grain-oriented ceramics (also referred to as textured ceramics) are known to exhibit a high soft piezoelectric response. However, the role of texturing in hard piezoelectric materials is not well understood and it has been difficult to obtain a balance of hard and soft properties in the same material. Here, we investigate the hard and soft piezoelectric behavior of [001]PC-textured 0.05Pb(Mn1/3Sb2/3)O3-0.95[0.4Pb(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3] (PMnS-PMN-PZT) ceramics to illustrate the influence of texturing degree. The results demonstrate that textured PMnS-PMN-PZT ceramics exhibit a 170% higher longitudinal mode piezoelectric coefficient (d33) with only 16% reduction in the mechanical quality factor (Qm). Random PMnS-PMN-PZT ceramics were found to exhibit a d33 of 259 pC/N and a Qm of 982, while textured ceramics sintered at the same temperature demonstrated a d33 of 445 and a Qm of 824. Electric field dependent x-ray diffraction is utilized to confirm the existence of internal bias generated from defect dipoles, providing the signature for hard behavior. Temperature dependent measurement of d33 and Qm for textured PMnS-PMN-PZT ceramics indicated high stability up to 120 °C.

Unprecedented conversion efficiency has been demonstrated for perovskite solar cells (PSCs), however, their stability and reliability continue to be challenge. Here, an effective and practical method is demonstrated to overcome the device stability issues in PSCs. A CF4 plasma treatment method is developed that results in the formation of a robust C–Fx layer covering the PSC device, thereby, imparting protection during the operation of solar cell. PSCs exposed to fluorination process showed excellent stability against water, light, and oxygen, displaying relatively no noticeable degradation after being dipped into water for considerable time period. The fluorination process did not have any impact on the morphology and electrical property of the top Spiro-OMeTAD layer, resulting in a conversion efficiency of 18.7%, which is identical to that of the pristine PSC. Under the continuous Xe lamp (AM 1.5G, 1 sun) illumination in ambient air for 100 h, the fluorinated PSCs demonstrated 70% of initial conversion efficiency, which is 4000% higher than that of the pristine PSC devices. We believe this breakthrough will have significant impact on the transition of PSCs into real world applications.

In the past five years, perovskite solar cells (PSCs) based on organometal halide perovskite have exhibited extraordinary photovoltaic (PV) performance. However, the PV measurements of PSCs have been widely recognized to depend on voltage scanning condition (hysteretic current density–voltage [J–V] behavior), as well as on voltage treatment history. In this study, we find that varied PSC responses are attributable to two causes. First, capacitive effect associated with electrode polarization provides a slow transient non-steady-state photocurrent that modifies the J–V response. Second, modification of interfacial barriers induced by ion migration can modulate charge-collection efficiency so that it causes a pseudo-steady-state photocurrent, which changes according to previous voltage conditioning. Both phenomena are strongly influenced by ions accumulating at outer interfaces, but their electrical and PV effects are different. The time scale for decay of capacitive current is on the order of seconds, whereas the slow redistribution of mobile ions requires several minutes. The authors gratefully acknowledge the financial support through the U.S. Army under Contract No. W15P7T-13-C-A910. The work at the National Renewable Energy Laboratory was supported by the U.S. Department of Energy SunShot Initiative under the Next Generation Photovoltaics 3 program (DE-FOA-0000990) under Contract No. DE-AC36-08-GO28308. S.P. and C.W. also appreciate support from the NSF I/UCRC: Center for Energy Harvesting Materials and Systems through Fundamental Research Program. The work at INAM-UJI was supported by Generalitat Valenciana project PROMETEO/2014/020.

Self-biased magnetoelectric (ME) composites, defined as materials that enable large ME coupling under external AC magnetic field in the absence of DC magnetic field, are an interesting, challenging and practical field of research. In comparison to the conventional ME composites, eliminating the need of DC magnetic bias provides great potential towards device miniaturization and development of components for electronics and medical applications. In this review, the current state-of-the-art of the different self-biased structures, their working mechanisms, as well as their main characteristics are summarized. Further, the nature and requirement of the self-biased magnetoelectric response is discussed with respect to the specific applications. Lastly, the remaining challenges as well as future perspective of this research field are discussed.

Electric field modulation of magnetic properties via magnetoelectric coupling in composite materials is of fundamental and technological importance for realizing tunable energy efficient electronics. Here we provide foundational analysis on magnetoelectric voltage tunable inductor (VTI) that exhibits extremely large inductance tunability of up to 1150% under moderate electric fields. This field dependence of inductance arises from the change of permeability, which correlates with the stress dependence of magnetic anisotropy. Through combination of analytical models that were validated by experimental results, comprehensive understanding of various anisotropies on the tunability of VTI is provided. Results indicate that inclusion of magnetic materials with low magnetocrystalline anisotropy is one of the most effective ways to achieve high VTI tunability. This study opens pathway towards design of tunable circuit components that exhibit field-dependent electronic behavior. DARPA MATRIX; office of basic energy science, department of energy [DE-FG02-09ER46674]; AFOSR [FA9550-14-1-0376] The authors gratefully acknowledge the financial support from DARPA MATRIX program. The authors would also like to thank the Center for Energy Harvesting Materials and Systems (CEHMS) for providing access to industrial experts and equipment. S.G. would like to acknowledge the support from office of basic energy science, department of energy, through grant number DE-FG02-09ER46674. H.-C.S. would like to acknowledge the support from AFOSR through grant number FA9550-14-1-0376.

Multilayer ceramic capacitors (MLCC) are widely used in consumer electronics. Here, we provide a transformative method for achieving high dielectric response and tunability over a wide temperature range through design of compositionally graded multilayer (CGML) architecture. Compositionally graded MLCCs were found to exhibit enhanced dielectric tunability (70%) along with small dielectric losses (< 2.5%) over the required temperature ranges specified in the standard industrial classifications. The compositional grading resulted in generation of internal bias field which enhanced the tunability due to increased nonlinearity. The electric field tunability of MLCCs provides an important avenue for design of miniature filters and power converters. DARPA MATRIX Program; Office of basic energy science, department of energy [DE-FG02-06ER46290]; office of naval research [N00014-16-1-3043] Financial support from DARPA MATRIX Program is acknowledged. The parallel computer simulations were performed on XSEDE supercomputers. D.M. and S.P. acknowledge the financial support from Office of basic energy science, department of energy (DE-FG02-06ER46290). Y.Y. acknowledges financial support from office of naval research through grant number (N00014-16-1-3043). Authors thanks AVX Corp. for the measurement on MLCC.

The PICO Collaboration wishes to thank SNOLAB and its staff for support through underground space, logistical, and technical services. SNOLAB operations are supported by the Canada Foundation for Innovation and the Province of Ontario Ministry of Research and Innovation, with underground access provided by Vale at the Creighton mine site. We are grateful to Kristian Hahn and Stanislava Sevova of Northwestern University and Bjorn Penning of the University of Bristol for their assistance and useful discussion. We wish to acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI) for funding. We acknowledge the support from National Science Foundation (NSF) (Grants No. 0919526, No. 1506337, No. 1242637, and No. 1205987). We acknowledge that this work is supported by the U.S. Department of Energy (DOE) Office of Science, Office of High Energy Physics (under Award No. DE-SC-0012161), by a DOE Office of Science Graduate Student Research (SCGSR) award, by Direccion General Asuntos del Personal Academico, Universidad Nacional Autonoma de Mexico (DGAPA-UNAM) through the grant Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT) No. IA100316 and by Consejo Nacional de Ciencia y Tecnologia (CONACyT) (Mexico) through Grant No. 252167, by the Department of Atomic Energy (DAE), the Government of India, under the Center of AstroParticle Physics II project (CAPP-II) at Saha Institute of Nuclear Physics (SINP), by the Czech Ministry of Education, Youth and Sports (Grant No. LM2015072), and by the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark (Grant No. CSD2009-00064). This work is partially supported by the Kavli Institute for Cosmological Physics at the University of Chicago through NSF Grant No. 1125897, and an endowment from the Kavli Foundation and its founder Fred Kavli. We also wish to acknowledge the support from Fermi National Accelerator Laboratory under Contract No. De-AC02-07CH11359, and Pacific Northwest National Laboratory, which is operated by Battelle for the U.S. Department of Energy under Contract No. DE-AC05-76RL01830. We also thank Compute Canada and the Center for Advanced Computing, ACENET, Calcul Quebec, Compute Ontario, and WestGrid for the computational support.