Detection of structural and magnetic transitions in La0.67Ba0.23Ca0.1MnO3 using the rf resonance technique

作者：Naik V B; Lam M C; Mahendiran R^*

来源：Journal of Magnetism and Magnetic Materials, 2010, 322(18): 2754-2757.

DOI：10.1016/j.jmmm.2010.04.021

• Manganite
• Dynamical magnetization
• rf absorption
• Structural transition

We report radio-frequency (rf) electrodynamics in polycrystalline La0.67Ba0.23Ca0.1MnO3 as a function of temperature and magnetic field using a home-built LC resonant circuit powered by an integrated chip oscillator. The resonance frequency (f(r)) of the oscillator and the power (P) absorbed by the sample are measured simultaneously. The paramagnetic to ferromagnetic phase transition in the absence of an external magnetic field is accompanied by a rapid decrease in both P and f(r) around the Curie temperature T-C=300 K. However, much below T-C, the f(r) shows a step-like anomaly around 165 K (195 K) while cooling (warming), which we attribute to a structural phase transition from high temperature rhombohedral (R (3) over barc) to low temperature orthorhombic (Imma) phase. The step-like anomaly in f(r) versus T disappears in a field of 300 G. Fractional changes as large as 19% in Delta f(r)/f(r) and 10% in Delta P/P are observed under H=1 kG around T-C. Our study suggests that the rf resonance technique is a versatile tool to study the magnetization dynamics as well as to investigate the structural phase transition in manganites.

• 出版日期2010-9