Journal of Physics, Condensed Matter 2011-08-24

Evidence of two distinct dynamical freezing processes in single-layered perovskite La(0.7)Sr(1.3)CoO4.

Jinhua Mao, Yu Sui, Xingquan Zhang, Xianjie Wang, Yantao Su, Yang Wang, Yi Wang, Zhiguo Liu, Ruibin Zhu, Xiaoyang Liu, Wanfa Liu

Index: J. Phys. Condens. Matter 23(33) , 336001, (2011)

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Abstract

The static and dynamic features of magnetization have been investigated in terms of dc magnetization, ac susceptibility, and memory effects on single-layered perovskite La(0.7)Sr(1.3)CoO(4). The results indicate that short-range ferromagnetic clusters coexist with the glassy magnetic state, i.e., a cluster-glass phase between T(f) and T(G) and a spin-glass-like phase below T(f). The clear evidence of memory effects in the dc magnetization is also observed below T(f) and T(G), respectively. These two glassy states with cooperative relaxation processes may derive from the different interaction processes among nanoscale ferromagnetic clusters mediated by the matrix, which is influenced by changing the spin state of Co(3+) ions in spontaneously phase-separated cobaltite.© 2011 IOP Publishing Ltd