Structural first-order transformation in La_2/3Ba_1/3MnO₃: ESR study

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• 作者：D.M. Polishchuk ; A.I. Tovstolytkin ; Elena Fertman ; Vladimir Desnenko ; Anatoly Beznosov ; Marcela Kaj¨¾akov¨¢ ; Alex ; er Feher
• 关键词：Manganite ; Phase separation ; Martensite ; Static magnetization ; Electron-spin resonance
• 刊名：Journal of Magnetism and Magnetic Materials
• 出版年：2012
• 出版时间：December, 2012
• 年：2012
• 卷：324
• 期：24
• 页码：4225-4230
• 全文大小：628 K

文摘

We have studied by the electron-spin resonance (ESR) and static magnetic field techniques, the La_2/3Ba_1/3MnO₃ perovskite, which was previously shown to exhibit a martensitic phase transformation in the vicinity of T_s¡«200 K [Physical Review B dFont"">68, 054109 (2003)], leading to its structural phase-segregated state. Resonant absorptions reveal that in the temperature interval from 100 K to 340 K the compound represents a mixture of two ferromagnetic phases possessing different magnetizations, in varying proportions depending on the temperature, and a small amount of a paramagnetic phase. The results agree well with the previous neutron diffraction study. Applied in the ESR experiments, magnetic fields (2-6 kOe) strongly affect the magnetization curves: even magnetic field as high as 700 Oe modifies the anomaly in the phase transformation region and removes the difference between the zero-field cooled and field-cooled magnetization curves, which implies that the difference in the magnetic susceptibility of the coexisting phases is small and the magnetic domain configuration can be easily changed.