resumo
Magnetic and thermodynamic properties of polycrystalline multiferroic Bi0.65La0.35Fe0.5Sc0.5O3 synthesized under high-pressure and high-temperature conditions are reported. Magnetic properties were studied using a SQUID magnetometer technique over the temperature range of 5-300 K in magnetic fields up to H-10 kOe. The field dependent magnetization M(H) was measured in magnetic fields up to 50 kOe at different temperatures up to 230 K after zero-field cooling procedure. A long-range magnetic ordering of the AFM type with a weak FM contribution occurs below the Neel temperature T-N 237 K. Magnetic hysteresis loops taken below TN show a huge coercive field up to H-c 0 kOe. A strong effect of magnetic field on the magnetic properties of the compound has been found. Derivative of the initial magnetization curves demonstrates a temperature-dependent anomaly in fields of H=15-25 kOe. Besides, an anomaly of the temperature dependent zero-field cooled magnetization measured in magnetic fields of 6-7 kOe has been found. Origin of both anomalies is associated with inhomogeneous magnetic state of the compound. The heat capacity has been measured from 2 K up to room temperature and a significant contribution from the magnon excitations at low temperatures has been detected. From the low-temperature heat capacity, an anisotropy gap of the magnon modes of the order 3.7 meV and Debye temperature T-D=89 K have been determined.
palavras-chave
FERROELECTRICITY
categoria
Materials Science; Physics
autores
Fertman, EL; Fedorchenko, AV; Khalyavin, DD; Salak, AN; Baran, A; Desnenko, VA; Kotlyar, OV; Cizmar, E; Feher, A; Syrkin, ES; Vaisburd, AI; Olekhnovich, NM; Pushkarev, AV; Radyush, YV; Stanulis, A; Kareiva, A
nossos autores
Andrei Salak
Investigador Principalagradecimentos
This work was supported by project TUMOCS. This project has received funding from European Union Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 645660. Also this work was supported by the Slovak Grant Agency VEGA 1/0145/13. O. Kotlyar acknowledges the financial support provided by the National Scholarship Programme of the Slovak Republic (SAIA) (Grant No. 15505). We are grateful to M. F. Kharchenko, the Academician of NAS of Ukraine, for help and fruitful discussions.