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Growth of high-quality graphene on germanium is to date only reported at growth temperatures near the substrate melting point. Direct integration of graphene growth into technological processes would, however, require a significantly lower growth temperature. Accordingly, we investigated the influence of growth temperature on the quality of graphene on Ge(001), Ge(110), and Ge(111). We found that increased defect density as indicated by Raman spectroscopy correlates with topographically protruding carbon defect clusters as indicated by scanning tunneling microscopy. The Raman quality of graphene on Ge(001) and Ge(110) grown at 850 °C is clearly limited by defects within the relatively large grains and not by grain boundaries, whereas the quality of graphene on Ge(111) additionally suffers from small grain size. We explain the decreased graphene quality by too weak substrate-mediated etching of defective carbon structures. Finally, we discuss potential ways to increase the rate of carbon etching. [ABSTRACT FROM AUTHOR]

Graphene epitaxy on germanium by chemical vapor deposition is a promising approach to integrate graphene into microelectronics, but the synthesis is still accompanied by several challenges such as the high process temperature, the reproducibility of growth, and the formation of etch pits during the process. We show that the substrate cleaning by preannealing in molecular hydrogen, which is crucial to successful and reproducible graphene growth, requires a high temperature and dose. During both substrate cleaning and graphene growth, etch pits can develop under certain conditions and disrupt the synthesis process. We explain the mechanisms how these etch pits may form by preferential evaporation of substrate, how substrate topography is related to the state of the cleaning process, and how etch pit formation during graphene growth can be controlled by choice of a sufficiently high precursor flow. Our study explains how graphene can be grown reliably on germanium at high temperature and thereby lays the foundation for further optimization of the growth process. [ABSTRACT FROM AUTHOR]

A novel transistor with a graphene base embedded between two n-type silicon emitter and collector layers (graphene-base heterojunction transistor) is fabricated and characterized electrically. The base voltage controlled current of the device flows vertically from the emitter via graphene to the collector. Due to the extremely short transit time for electrons passing the ultimately thin graphene base, the device has a large potential for high-frequency RF applications. The transistor exhibits saturated output currents and a clear modulation of the collector current by means of the graphene base voltage. The vertical transfer current from the emitter via the graphene base to the collector is much lower than expected from device simulations. A comparison of the graphene-base transistor and a reference silicon n-p-n bipolar transistor is performed with respect to the main DC transistor characteristics. A common-emitter gain of larger than one has been achieved for the reference device while the graphene-base transistor so far exhibits a much lower gain. [ABSTRACT FROM AUTHOR]

The basic building blocks of every neural network are neurons and their inter-cellular connections, called synapses. In nature, synapses play a crucial role in learning and memory, since they are plastic, which means that they change their state depending on the neural activity of the respectively coupled neurons. In neuromorphic systems, the functionality of neurons and synapses is emulated in hardware systems by employing very-large-scale integration technology. In this context, it seems rather natural to use non-volatile memory technology to mimic synaptic functionality. In particular, memristive devices are promising candidates for neuromorphic computing, since they allow one to emulate synaptic functionalities in a detailed way with a significantly reduced power usage and a high packing density. This tutorial aims to provide insight on current investigations in the field to address the following fundamental questions: How can functionalities of synapses be emulated with memristive devices? What are the basic requirements to realize artificial inorganic neurons and synapses? Which material systems and device structures can be used for this purpose? And how can cellular synaptic functionality be used in networks for neuromorphic computing? Even if those questions are part of current research and not yet answered in detail, our aim is to present concepts that address those questions. Furthermore, this tutorial focuses on spiking neural models, which enables mimicking biological computing as realistically as possible. [ABSTRACT FROM AUTHOR]

Twin-free epitaxial cubic (111) praseodymium sesquioxide films were prepared on Si(111) by hexagonal-to-cubic phase transition and synchrotron radiation grazing incidence X-ray diffraction and transmission electron microscopy were applied to characterize the phase transition and the film structure. Transmission electron microscopy shows that the phase transition is accompanied by an interface reaction at the oxide/Si(111) boundary.

N-type doped amorphous hydrogenated silicon (a-Si:H) is deposited on top of graphene (Gr) by means of very high frequency (VHF) and radio frequency plasma-enhanced chemical vapor deposition (PECVD). In order to preserve the structural integrity of the monolayer graphene, a plasma excitation frequency of 140 MHz was successfully applied during the a-Si:H VHF-deposition. Raman spectroscopy results indicate the absence of a defect peak in the graphene spectrum after the VHF-PECVD of (n)-a-Si:H. The diode junction between (n)-a-Si:H and graphene was characterized using temperature dependent current-voltage (IV) and capacitance-voltage measurements, respectively. We demonstrate that the current at the (n)-a-Si:H-graphene interface is dominated by thermionic emission and recombination in the space charge region. The Schottky barrier height (qΦB), derived by temperature dependent IV-characteristics, is about 0.49 eV. The junction properties strongly depend on the applied deposition method of (n)-a-Si:H with a clear advantage of the VHF(140 MHz)-technology. We have demonstrated that (n)-a-Si:H-graphene junctions are a promising technology approach for high frequency heterojunction transistors. [ABSTRACT FROM AUTHOR]

The effects of the (111) texture on the perpendicular magnetic anisotropy (PMA) of a Co/Ni ML has been studied. (111)fee oriented (Co(2A)/Ni(7A))(sub2) multilayered were prepared using molecular beam epitaxy. The magnetic multilayer film has significant waviness on its top and bottom surfaces, originating partly from the waviness already present, but further enhanced by differing surface free energies of Au and the magnetic elements.

Carbon nanotubes (CNTs) are a promising replacement for tungsten filaments as electron emitters in conventional x-ray sources, owing to their higher aspect ratio, superior mechanical stability, chemical inertness, and high electrical and thermal conductivities. Conditions for realizing the best emission behavior from CNTs have been formulated over the last few years. In this paper, we report the relatively less-investigated factor, namely, the influence of the nature of substrate material on the growth as well as field emission characteristics of large-area multiwalled CNTs for their practical application in medical x-ray sources. We compare the morphology of CNTs on a variety of substrates such as stainless steel, copper, molybdenum, graphite, few-layer graphene, and carbon nanowalls grown by thermal chemical vapor deposition following a simple drop-coating of catalyst. We find that CNTs grown on stainless steel and graphite show the best combination of emission characteristics under pulsed operation mode. These studies are helpful in selecting the optimum substrate material for field emission applications. Ex situ studies on field emission degradation of CNTs are presented towards the end. [ABSTRACT FROM AUTHOR]

The performance of magnetic susceptibility measurements on a series of strontium-borate-vanadate glasses for determining the ratio of valence states of the V ions is discussed. A weak antiferromagnetic interaction between V (super +4) ions was indicated by the negative Curie-Weiss temperature values in the range of 0 to -2.8 K.

The crystallographic and magnetic properties for various concentrations of Co(sub 1-x)Fe(sub x) alloys deposited in the pores of an alumina matrix produced by anodization in oxalic acid are examined. For magnetic fields parallel to the wires, the squareness of the hysteresis loops was found to be between 72 percent and 93 percent whereas for fields perpendicular to the wires, the squareness is less than 13 percent.

A study is conducted on the magnetic properties of multilayer structures with two magnetic layers of the same metal (Co) but with different crystallographic structures. It is shown that the single crystalline fcc Co layer has nearly ideal switching of the magnetization when the field was applied along the easy axis. On the other hand, the magnetization of the hcp Co layer changes smoothly within a wide field range because of its polycrystalline structure.

The conduction process as well as the unipolar resistive switching behavior of Au/HfO2/TiN metal-insulator-metal structures were investigated for future nonvolatile memory applications. With current-voltage measurements performed at different temperatures (200–400 K), the Poole–Frenkel effect as conduction process was identified. In particular, we extracted a trap energy level at [lowercase_phi_synonym]t=0.35±0.05 eV below the HfO2 conduction band to which a microscopic origin is tentatively assigned. From current-voltage measurements of Au/HfO2/TiN structures, low-power (as low as 120 μW) resistive switching was observed. The required forming process is shown to be an energy-induced phenomenon. The characteristics include electric pulse-induced resistive switching by applying pulses up to 100 μs and a retention time upon continuous nondestructive readout of more than 104 s. [ABSTRACT FROM AUTHOR]

We report the optical pumping of one-dimensional distributed feedback (DFB) conjugated polymer devices using a uniaxially aligned liquid crystalline polymer, poly(9,9-dioctylfluorene). We can independently select the alignment direction (via a rubbed polyimide layer) and the DFB structure (via nanoimprinting). In comparison with unaligned film, we show that lasing threshold is substantially reduced when absorption is parallel to the aligned direction (∼20.0 μJ cm-2 pulse-1). This is mainly due to the higher absorption coefficient estimated in the table by calculating the exciton densities at each threshold value. We also report the control of lasing wavelength through independent selection of alignment direction and DFB orientation, which is achieved through the control of the effective refractive index of waveguide (neff). [ABSTRACT FROM AUTHOR]

The achievement of sufficient capacitance-voltage linearity in metal-insulator-metal (MIM) capacitors with high permittivity (high-k) dielectrics is still a challenge, as the origin of the nonlinear behavior is still unclear. Based on fundamental physical mechanisms, such as electrostriction, Coulomb interaction between electrodes, and nonlinear optical effects, a microscopic model, which describes the nonlinearities in capacitance-voltage characteristics of high-k MIM capacitors, will be presented. The extended model, which includes stacked high-k dielectrics and interfacial layers, is able to predict the quadratic voltage capacitance coefficients as a function of the dielectric constant. The calculated coefficients are in suitable agreement with the experimental values of Al2O3-, Y2O3-, HfO2-, and Pr2Ti2O7-based MIM capacitors. [ABSTRACT FROM AUTHOR]

The stoichiometry, structure, and defects of self-assembled heteroepitaxial Ge nanodots on twin-free type B oriented cubic Pr2O3(111) layers on Si(111) substrates are studied to shed light on the fundamental physics of nanocrystal based nonvolatile memory effects. X-ray photoelectron spectroscopy studies prove the high stoichiometric purity of the Ge nanodots on the cubic Pr2O3(111)/Si(111) support system. Synchrotron based x-ray diffraction, including anomalous scattering techniques, was applied to determine the epitaxial relationship, showing that the heteroepitaxial Ge(111) nanodots crystallize in the cubic diamond structure with an exclusive type A stacking configuration with respect to Si(111). Grazing incidence small angle x-ray scattering was used in addition to analyze the average shape, size, and distance parameters of the single crystalline Ge nanocrystal ensemble. Furthermore, transmission electron micrographs report that partial dislocations are the prevailing extended defect structure in the Ge nanodots, mainly induced by surface roughness on the atomic scale of the cubic Pr2O3(111) support. [ABSTRACT FROM AUTHOR]

Engineered dielectrics combined with compatible metal electrodes are important materials science approaches to scale three-dimensional trench dynamic random access memory (DRAM) cells. Highly insulating dielectrics with high dielectric constants were engineered in this study on TiN metal electrodes by partly substituting Al in the wide band gap insulator Al2O3 by Pr cations. High quality PrAlO3 metal-insulator-metal capacitors were processed with a dielectric constant of 19, three times higher than in the case of Al2O3 reference cells. As a parasitic low dielectric constant interface layer between PrAlO3 and TiN limits the total performance gain, a systematic nondestructive synchrotron x-ray photoelectron spectroscopy study on the interface chemistry of PrxAl2-xO3 (x=0–2) dielectrics on TiN layers was applied to unveil its chemical origin. The interface layer results from the decreasing chemical reactivity of PrxAl2-xO3 dielectrics with increasing Pr content x to reduce native Ti oxide compounds present on unprotected TiN films. Accordingly, PrAlO3 based DRAM capacitors require strict control of the surface chemistry of the TiN electrode, a parameter furthermore of importance to engineer the band offsets of PrxAl2-xO3/TiN heterojunctions. [ABSTRACT FROM AUTHOR]

Praseodymium (Pr) silicate dielectric layers were prepared by oxidation and subsequent N2 annealing of thin Pr metal layers on SiO2/Si(100) substrates. Transmission electron microscopy studies reveal that the resulting dielectric has a bilayer structure. Nondestructive depth profiling by using synchrotron radiation x-ray photoelectron spectroscopy shows that, starting from the substrate, the dielectric stack is composed of a SiO2-rich and a SiO2-poor Pr silicate phase. Valence and conduction band offsets of about 2.9 and 1.6 eV, respectively, between the dielectric and the Si(100) substrate bands were deduced. Pr silicate films with an equivalent oxide thickness of 1.8 nm show approximately three orders of magnitude lower leakage currents than silicon oxynitride references. Capacitance versus voltage measurements of the Pr silicate/Si(100) system report a flat band voltage shift of 0.22 V, an effective dielectric constant of about 11 and a reasonably good interface quality with an interface state density on the order of 1011 cm-2. Experimental results are supplemented by ab initio considerations which review the most probable mechanisms of fixed charge formation in the Pr silicate layers. [ABSTRACT FROM AUTHOR]

The structure of epitaxial Si overlayers on a hexagonal Pr2O3(0001)/Si(111) substrate system was investigated by a combination of x-ray reflectivity, specular x-ray diffraction, off-specular grazing incidence x-ray diffraction, and transmission electron microscopy. The Pr2O3 film grows on the Si(111) substrate in the (0001)-oriented hexagonal phase matching the in-plane symmetry by aligning the [1010] oxide along the bulk [011] Si direction. The hexagonal Pr2O3(0001) surface induces the growth of [111]-oriented cubic-Si epilayers exhibiting a microstructure which is composed of two types of domains. The ABC-stacked domains preserve the crystal orientation of the substrate, while the CBA-stacked domains are rotated by 180°. A depth profile of the chemical composition of the epi-Si/Pr2O3/Si(111) material stack was recorded by combining ion-beam sputtering techniques with x-ray photoelectron spectroscopy. [ABSTRACT FROM AUTHOR]

The structure of ultrathin epitaxial Pr2O3 films on Si(111) was studied by synchrotron radiation-grazing incidence x-ray diffraction. The oxide film grows as hexagonal Pr2O3 phase with its (0001) plane attached to the Si(111) substrate. The hexagonal (0001) Pr2O3 plane matches the in-plane symmetry of the hexagonal Si(111) surface unit cell by aligning the (10&1bar;0)Pr2O3 along the (11&2bar;) Si directions. The small lattice mismatch of 0.5% results in the growth of pseudomorphic oxide films of high crystalline quality with an average domain size of about 50 nm. The critical thickness tc for pseudomorphic growth amounts to 3.0± 0.5 nm. The relaxation of the oxide film from pseudomorphism to bulk behavior beyond tc causes the introduction of misfit dislocations, the formation of an in-plane small angle mosaicity structure, and the occurence of a phase transition towards a (111) oriented cubic Pr2O3 film structure. The observed phase transition highlights the influence of the epitaxial interface energy on the stability of Pr2O3 phases on Si(111). A mechanism is proposed which transforms the hexagonal (0001) into the cubic (111) Pr2O3 epilayer structure by rearranging the oxygen network but leaving the Pr sublattice almost unmodified. [ABSTRACT FROM AUTHOR]

The conduction processes as well as the unipolar resistive switching behavior of Au/Hf[O.sub.2]/TiN metal-insulator-metal structures were explored to understand their use for future nonvolatile memory applications. The current-voltage measurements obtained for Au/Hf[O.sub.2]/TiN structures explain the observed low-power resistive switching process.

The optical pumping of one-dimensional distributed feedback (DFB) conjugated polymer devices is described by using a uniaxially aligned liquid crystalline polymer (poly(9,9-dioctylfluorene)). The control of lasing wavelength through independent selection of alignment direction and DFB orientation is achieved through the control of the effective refractive index of waveguide.

High frequency dynamic studies are performed on Permalloy nanosized arrays of different aspect ratios by using network analyzer ferromagnetic resonance (FMR). The frequencies are strongly dependent upon the aspect ratio and the frequency linewidths of the strips are dependent on the aspect ratio.

The magnetic interactions in large arrays of ordered magnetic nanowires are examined by using modified Henkel plots. The dependence of the remanence curves on the field history has shown that even for magnetic nanowire systems with high geometric anisotropy, the magnetic pole structure of the nanowires can be complex.

The magnetic and electrical properties of [La.sub.0.4][Ca.sub.0.6][Mn.sub.1-y][Cr.sub.y][O.sub.3] polycrystalline samples (y = 0.02, 0.04 and 0.06) prepared by sol-gel method are examined. A large field-induced behavior is seen in both the magnetoresistance (MR) and magnetization at temperatures correlated to the ferromagnetic semimetallic phase, which has resulted in large MR at the lowest temperatures.

A study examines the stoichiometry, structure, and defects of slef-assembled heteroepitaxial Ge nanodots on twin-free type B oriented cubic [Pr.sub.2][O.sub.3](111) layers on Si(111) substrates. Results indicate that mutually isolated hemispherical Ge nanocrystals can be grown on cubic [Pr.sub.2][O.sub.3](111)/Si(111) support systems.

Highly insulating dielectrics dielectric with high dielectric constants are engineered on TiN metal electrodes by partly substituting Al in the wide band gap insulator [Al.sub.2][O.sub.3] by Pr cations. PrAl[O.sub.3] based dynamic random access memory (DRAM) capacitors needs strict control of the surface chemistry of the TiN electrode, a parameter that is important for engineering the band offsets of [Pr.sub.x][Al.sub.2-x][O.sub.3]/TiN heterojunctions.

Synthesis of cobalt-ferrite nanoparticles by ion-exchanging sulfonated polystyrene resin with iron and cobalt chlorides is presented. The size of the nanoparticles, the composition of the Fe-Co ferrites, and the blocking temperature are found to depend upon whether divalent or trivalent Fe is used in the synthesis.

The low-temperature dynamics of a magnetic nanoparticle system (gama-Fe2O3-alginate nanocomposite with average particle size around 4 nm) are studied superconducting quantum interference device measurements. Observations indicate that the dynamics of this nanoparticle system are governed a wide distribution of particle relaxation times.

The synthesis and elucidation of the magnetic properties of iron oxide nanoparticles precipitated inside alginate hydrogels are studied. The results indicated that the distribution of the particle size and saturation magnetization and coercive field values are smaller for the nanoparticles precipitated in alginate hydrogels as compared to those in the polystyrene resin matrix.

The structure of ultrathin epitaxial Pr2O3 films on Si(111) is studied by synchrotron radiation-grazing incidence x-ray diffraction. The oxide film grows as hexagonal Pr2O3 phase with its (0001) plane attached to the Si(111) substrate.

A simple computational model that reproduces the hysteresis and magnetization curves along the easy magnetization axis for hexagonally ordered Co0.45Fe0.55 alloy nanowire arrays is discussed. Simulations on magnetostatically interaction nanowire arrays using a simplified model that considers dipole-dipole-like interactions have been performed.

The magnetic characteristics of electrodeposited Co0.45Fe0.55 alloy nanowire arrays in porous anodic alumina templates are discussed. Evidence for inhomogeneous magnetization states in microscopic nanowires was found by performing macroscopic magnetization measurements.

Presents a study which examined the effects of extreme-ultraviolet (XUV) illumination on particle beam fusion accelerator-I (PBFA-I) magnetically insulated ion diode. Types of detectors used to look for plasma or neutrals crossing the anode-cathode gap; Description of physical processes that occur in the ion diode during XUV illumination; Precursor pulse space-charge conduction limits in regions of XUV illumination.

Presents a series of experiments which explored the scaling of Applied-B ion diode operation from the Particle Beam Fusion Accelerator-I. Descriptions of the accelerator and Applied-B diode; Discussion of power flow considerations; Diagnostics used in the experiments.

The thickness-dependent domain structure data on the epitaxial Co(0001) films as well as similar magnetic force microscopy data on epitaxial Ni(111) films prepared in our laboratory by molecular beam epitaxy (MBE) using a one-dimensional periodic model with titled partial flux closure domains is presented. Any tilt of the moments in the flux closure domains correspondingly gives rise to an in-plane magnetization in agreement with experimental observations for these films.

The magnetic and electrical properties of electron-doped manganite La0.4Ca0.6Mn1-yCryO3 polycrystalline samples (y=0.02, 0.04, and 0.06) prepared by a sol-gel technique have been investigated between 5 and 325 K in magnetic fields ranging from 0 to 5 T. Both the M-T and M-H data indicate that these Cr-doped manganites exhibit multiple ferromagnetic phases in which the relative amounts of each phase and temperatures of their appearance change with Cr content. The temperature dependence of the zero-field resistivity indicates that a transition occurs below 150 K from an insulating (semiconducting) behavior to a behavior exhibiting a temperature-independent plateau with the magnitude of a semimetal. In addition a large field-induced behavior is found in both the magnetoresistance and magnetization at temperatures correlated to the ferromagnetic semimetallic phase being induced, which results in a large magnetoresistance at the lowest temperatures. [ABSTRACT FROM AUTHOR]

The magnetic and electrical properties of electron-doped manganite La0.4Ca0.6Mn1-yCryO3 polycrystalline samples (y=0.02, 0.04, and 0.06) prepared by a sol-gel technique have been investigated between 5 and 325 K in magnetic fields ranging from 0 to 5 T. Both the M-T and M-H data indicate that these Cr-doped manganites exhibit multiple ferromagnetic phases in which the relative amounts of each phase and temperatures of their appearance change with Cr content. The temperature dependence of the zero-field resistivity indicates that a transition occurs below 150 K from an insulating (semiconducting) behavior to a behavior exhibiting a temperature-independent plateau with the magnitude of a semimetal. In addition a large field-induced behavior is found in both the magnetoresistance and magnetization at temperatures correlated to the ferromagnetic semimetallic phase being induced, which results in a large magnetoresistance at the lowest temperatures. [ABSTRACT FROM AUTHOR]

Samples of maghemite and cobalt-ferrite nanoparticles (sizes, 3–10 nm) were prepared by cross-linking sulfonated polystyrene resin with aqueous solutions of (1) FeCl2, (2) 80%FeCl2+20%CoCl2, (3) FeCl3, and (4) 80%FeCl3+20%CoCl2 by volume. Chemical analysis, x-ray powder-diffraction, and 57Fe Mössbauer spectroscopic measurements show that samples 1 and 3 consist of γ-Fe2O3 nanoparticles (sizes, ∼10 and 3 nm) and sample 2 and 4 consist of CoxFe3-xO4 nanoparticles (sizes, ∼10 and 4 nm). The temperature dependence of the zero-field-cooled and field-cooled magnetizations at low temperatures, together with a magnetic hysteresis in the M versus H data below blocking temperatures, demonstrate superparamagnetic behavior. The introduction of Co in the iron oxide-resin matrix results in an increase in the blocking temperature of nanoparticles. [ABSTRACT FROM AUTHOR]

The low-temperature dynamics of a magnetic nanoparticle system (γ-Fe2O3-alginate nanocomposite with average particle size around 4 nm) have been studied by superconducting quantum interference device measurements. Using different temperature and field protocols, memory phenomena in the dc magnetization and magnetic relaxation have been observed at temperatures below its blocking temperature TB=37 K. However, aging experiments show an absence of any waiting time dependence in the magnetization relaxation. These observations indicate that the dynamics of this nanoparticle system are governed by a wide distribution of particle relaxation times which arise from the distribution of particle sizes and weak interparticle interactions. [ABSTRACT FROM AUTHOR]

Co[SUB0.45]Fe[SUB0.55] alloy nanowires with 12 to 35 nm diameter and 12 μm length were fabricated by electrodeposition in porous anodic alumina templates. The initial magnetization curves reveal that the zero magnetization state is not unique and is determined by the field history (ac demagnetization process) leading to the zero average moment state. For ac demagnetization processes with the field applied parallel to the nanowire axis, the subsequent magnetization curves suggest that an individual nanowire behaves as a single domain with neighboring nanowires being antiparallel to each other in the zero magnetization state. However, for a demagnetization process with the field applied perpendicular to the nanowires, a different zero magnetization state is created in which the individual nanowires consist of multidomains having opposite axial orientations. These results are consistent with the asymmetric (symmetric) behavior found in the minor hysteresis loops measured after perpendicular (parallel) ac demagnetization on these nanowire arrays. [ABSTRACT FROM AUTHOR]

Presents a study which examined the nonbolometric responses to microwave irradiation on yttrium barium copper oxide thin films. Fabrication of the thin films; Possible explanation for the responses; Conclusion.

Presents a study that examined the long-range helical magnetic order in a single crystal of the dilute alloy yttrium (Y)[sub0.97] -dysprosium[sub0.03] using neutron diffraction. Effect of the combination of alloys of heavy rare-earth metals with Y; Description of the neutron scattering measurements used.

Presents a study which examined the magnetic field dependence of the spin structure in single crystals of yttrium[sub 1-x]gadolinium[sub x]. Methods; Results of the application of the magnetic field on the satellite of origin; Analysis of the magnetic scattering from the helical spin-density wave (SDW) as compared to the linear SDW.

Presents a study which measured the precise heat capacity in magnetic fields on a cobalt oxide-aluminum[sub 2] oxygen [sub 3]-silicon oxide spin glass. Analysis of the magnetic field dependence; Experimental features observed in spin glass research; Conclusions.