Evidence for spin glass state of NdCo1-xNixO 3 (x = 0.3- 0.5)

Abstract

Low-temperature magnetic properties of single phase NdCo1−x Ni xO3(x = 0.3−0.5) have been studied using ac and dc magnetic susceptibility measurements. Nickel substituted samples have been found to exhibit a different magnetic state at low temperature as compared to pristine NdCoO3. The temperature dependent dc magnetization M (T) revealed the presence of a sharp cusp occurring at characteristic temperatures TP , for x = 0.3, 0.4, 0.5. Below TP , clear effect of magnetic field can be seen in M (T) curves and TP decreases with increasing magnetic field as well as Ni substitution content. The isothermal magnetization measurements at low temperatures shows small unsaturated hysteresis loop at lowest temperature (10 K). The ac susceptibility results show a clear frequency dependent feature. These results are analyzed to distinguish superparamagnetic and spin glass behavior by using Néel-Arrhennius, Vogel-Fulcher law, and power law fitting. This analysis ruled out the superparamagnet like state and suggests the presence of significant inter-cluster interactions, giving rise to spin-glass like cooperative freezing