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In an effort to explore new electronic devices with multiple functionalities, there are numerous studies of depositing perovskite oxides on flexible substrates to replace rigid silicon‐based wafer in device applications. In this study, the growth of pseudocubic SrRuO3 single‐crystal thin film on a transparent and flexible muscovite is established. The experimental results confirm that the Curie temperature TC and the magnetic properties can be effectively tuned via the mechanical strain due to the facilitation of flexible substrate. It is found that the tensile strain increases while the compressive strain decreases the spontaneous magnetization for the thin film suffering the same ±0.24% strain. Based on the study of critical behavior, the critical exponents β = 0.543(19) and γ = 1.262(1) with the critical temperature TC = 159.04(5) K and TC = 159.10 K, respectively, are obtained by the modified Arrott plot. The set of critical exponents matches well with Widom scaling relation and the scaling equation, indicating these critical exponents are intrinsic for SrRuO3 thin films. Moreover, it is achieved that the SrRuO3 thin films exhibit a long‐range interaction coupled with 3D‐Heisenberg type. [ABSTRACT FROM AUTHOR]

We have studied the magnetic coupling property, magnetic entropy change, and magnetic phase transition behavior of ternary alloy Ce 1. 3 Pr 0. 7 Co 7 . It exhibits a typical paramagnetic–ferromagnetic phase transition at T C = 2 1 8  K and this phase transition is verified to be second order by the scaling theory. Based on the data of isothermal magnetization measured around T C , we obtained the variation of its magnetic entropy change under the different magnetic fields but it only shows a smaller entropy change value. Density functional calculations confirm that the extra magnetic interaction originates from the Pr-Pr exchange interactions, which yields anomalous magnetic coupling with Co-Co (Ce-Ce) exchange interactions. One phenomenological model is suggested to understand anomalous magnetic behavior observed in the present intermetallic compounds. [ABSTRACT FROM AUTHOR]

The magnetic and electronic transport properties of the lightly doped SrRu1-x Fex O3 (x ≤ 0.15) have been studied. All the samples show a paramagnetic-ferromagnetic phase transition and hysteresis effect. With the increase of Fe, the temperature of magnetic phase transition decreases but coercive field increases indicting the existence of antiferromagnetic interaction and magnetic-crystalline anisotropy. In low temperature, all the doping samples exhibit an insulating behavior while metal feature appears only at x ≤ 0.10 samples. The induced disorder suppresses the itinerant property of Ru 4d electron due to Fe random occupation. As a result, the ferromagnetism is weakened and metal-insulator transition is suppressed. [ABSTRACT FROM AUTHOR]

We report a detailed study of magnetic properties in manganite (LaPr)CaMnO. In contrast to the usual beliefs, it shows an abnormal upturn deviation from the Curie-Weiss law on the inverse susceptibility curve. Such a non-Griffiths-like phase is further confirmed from the inverse double integrated intensities of electron paramagnetic resonance spectrum. Because La $$^{3+}$$ ions are substituted by Pr $$^{3+}$$ ions with 50% concentrations, the ratio of three ions (La $$^{3+}$$ , Pr $$^{3+}$$ , Ca $$^{2+}$$ ) is close to 1 on A-site sublattice. As a result, some short-range antiferromagnetic (CO AFM) phases come into being in the system due to the existence of localized charge ordering states. Therefore, the upturn deviation from Curie-Weiss law originates from the appearance of short-range CO AFM correlations above $$T_{\text{C}}$$ . Additionally, a magnetic field-driven-metamagnetic transition is found, which gives a main contribution for the large magnetic entropy change (MEC) observed in this sample. Both the Arrott plot and the renormalized MEC curves testify that this transition belongs to first-order magnetic transition. The insignificant hysteresis loop indicate that the inevitable thermal hysteresis can be ignored in the present first-order material implying that it is a potential candidate for the cryogenic temperature magnetic refrigeration. [ABSTRACT FROM AUTHOR]

The critical exponents of second-order phase transition were deduced from magnetic entropy change. Using the magnetic field dependence of entropy change and the Widom scaling relation, some relevant critical exponents can be calculated directly from them. Based on critical exponents, a corresponding Arrott plot can be established as an initial model. Through a limited nonlinear fitting, we can obtain the final critical exponents. This method eliminates the drawbacks of the routine method which relies on the subjective selection of an initial model and involves the multi-step nonlinear fitting process. It was applied to the manganite NdSrCaMnOto verify its utility and feasibility. The spontaneous magnetization obtained using the final critical exponents is consistent with that deduced from the isothermal magnetization measurements, indicating that the utilization of the magnetic field dependence of magnetic entropy change to determine critical exponents is a valid method. [ABSTRACT FROM AUTHOR]

In this paper, we present the investigations of electron paramagnetic resonance on perovskite manganite PrSrMnO and Ga-doped PrSrMnGaO. The temperature dependent paramagnetic resonance spectra parameters (effective g-factor, peak-to-peak linewidth Δ H and double integrated intensities) have been used to study the paramagnetic spin correlations and spin dynamics. The gradual increase of effective g-factor is attributed to the presence of orbital ordering above T. The model fittings of temperature dependent double integrated intensities reveal Arrhenius law is appropriate for describing PrSrMnGaO instead of PrSrMnO system. As for PrSrMnO, the broadening of linewidth with the temperature increase origins from the contribution of small polaron hopping in the PM regime. However, as for PrSrMnGaO, the broadening of EPR linewidth can be understood with the spin-lattice relaxation mechanism. [ABSTRACT FROM AUTHOR]

The mechanical stress effect on the crystallization behaviour of Ge2Sb2Te5(GST) thin films is carefully investigated by electrical resistance measurements. It is found that the crystallization temperature of GST films increases as external compressive stress is applied, while the crystallization temperature decreases under tensile stress. We also find that the uneven distribution of extrinsic stress can widen the span of transition temperature. These results clearly demonstrate that mechanical stress plays an important role during the crystallization process of GST films and may further influence the reliability and storage speed of relevant devices. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Electron paramagnetic resonance studies have been performed on the perovskite manganite Pr0.55Sr0.45MnO3. The various spectrum parameters including line width, effective g-value and double-integrated intensities have been analyzed in detail. The changes of g-value and linewidth are indicative of the presence of strong spin-lattice interaction in the paramagnetic regime. The lattice distortion causes the appearance of localized carriers and the formation of a small polaron. Therefore, the large activation energy obtained from two different methods implies that a strong spin-lattice correlation exists in Pr0.55Sr0.45MnO3. [ABSTRACT FROM AUTHOR]

Abstract: Pulsed-laser-deposited polycrystalline BaTiO3/SrTiO3 multilayered films on Pt/Ti/SiO2/Si substrates have been fabricated with interfacial modification through lowering the oxygen pressure during the time interval in between two adjacent depositions. It is found that the formation of the heterolayered structure is essential to get the dielectric enhancement. Such heterolayered films have large dielectric constant of 1201 with a loss tangent below 0.1 at 10KHz. This is about two times that of the identically prepared Ba0.5Sr0.5TiO3/Ba0.5Sr0.5TiO3 homolayered and uniform Ba0.5Sr0.5TiO3 films. The enhancement of dielectric properties is attributed to the presence of the interfacial regions with controllable space charges due to the formation of oxygen vacancies at lower oxygen pressure. [Copyright &y& Elsevier]

• The electronic phase separation has been observed in La 0.8 Sr 0.2 MnO 3. • The state of magnetic skyrmion exists in the temperature region of 290 K–306 K. • A large DM interaction exists in the interface of LaMnO 3 /SrMnO 3. Magnetic skyrmions, being one of the most promising candidates for the next generation memory-type application due to their nanometer-size and efficient current-driven dynamics, are mainly found and studied in alloy helimagnets in which the spin-orbit coupling induced by Dzyaloshinskii-Moriya interaction (DMI) enables noncollinear spin alignment and skyrmion formation. In this paper, we report a possible finding of skyrmions crystal near room-temperature in centrosymmetric structures perovskite manganite La 0.8 Sr 0.2 MnO 3 (LSMO). Based on the measurements of isothermal magnetization around the Curie temperature (∼298 K), an unusual magnetic behavior of a discontinuous magnetization was observed and existed only at moderate magnetic field region together with a narrow temperature range from 306 to 290 K. Apart from this range, all curves return to conventional magnetic behavior of continuous change with external magnetic field. This characteristic has been frequently observed in some reported helimagnets (such as FeGe, MnSi), implying the possible existence of skyrmions crystal in LSMO. To further unveil the physical origin and underlying mechanisms, we performed the first-principles calculation for LSMO compound and a large DMI (Δ E DMI = 13.46 meV, d 1 = 1.68 meV) was found to exists at the interface of LaMnO 3 / SrMnO 3 layers. This result not only supports our experimental findings in the present composition but also is consistent with the formation mechanism of magnetic skyrmions. [ABSTRACT FROM AUTHOR]

Magnetic and electronic transport properties of perovskite manganite La 0.6 Er 0.1 Sr 0.3 MnO 3 have been thoroughly examined through the measurements of magnetization, electron paramagnetic resonance(EPR), and resistivity. It was found that the substitution of Er 3+ for La 3+ ions introduced the chemical disorder and additional strain in this sample. An extra resonance signal occurred in EPR spectra at high temperatures well above T C gives a strong evidence of electronic phase separation(EPS). The analysis of resistivity enable us to identify the polaronic transport mechanism in the paramagnetic region. At low temperature, a new ferromagnetic interaction generates in the microdomains of Er 3+ -disorder causing the second increase of magnetization. However, the new ferromagnetic interaction does not improve but decreases electronic transport due to the enhancement of interface resistance among neighboring domains. In view of a really wide temperature region for the EPS existence, this sample provides an ideal platform to uncover the evolution law of different magnetic structures in perovskite manganites.