Origin of the Downturn in Inverse Susceptibility Observed above the Curie Temperature in Perovskite Manganites

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2005,（6）
• 页码范围: 1511-1514
• 页数: 4页
• 语种: 英文

摘要

The measurement of low-field susceptibility X as a function of temperature T for La2/3Ca1/3MnO3 shows a significant downturn in 1/x(T) above the Curie temperature TC, a behaviour generally observed in perovskite manganites. Such a downturn is argued to be due to the segregation of ferromagnetic clusters with larger spins in the paramagnetic matrix. Based on this consideration, a phenomenological expression for x(T) is proposed,in which the total susceptibility is assumed to be a sum of two susceptibilities arising from magnetic entities in the PM background and the FM clusters with T-dependent effective spins, respectively. The result is in good agreement with the experimental data obtained in La2/3Ca1/3MnO3.