Spin glass behavior of amorphous Fe5(InTe4)3

Abstract

The amorphous phases of Cr5(InTe4)3 and Fe5(InTe4)3 have been prepared via the precipitation reaction of the Zintl polyanion InTe−54 with Cr3+ and Fe3+ in aqueous solution, respectively. Their magnetic and conducting properties have been examined as a function of temperature. The high-temperature susceptibility of Cr5(InTe4)3 follows the Curie–Weiss law with θ=−30.2 K and C=1.65 emu/mole Cr atom. Cr5(InTe4)3 has a conductivity of 1.07×10−3 Ω−1 cm−1 at 300 K and is a semiconductor with Ea=0.20 eV. Fe5(InTe4)3 exhibits relatively high conductivity due to partial delocalization of electrons. Its conductivity is 7.41 Ω−1 cm−1 at 300 K, and shows little temperature dependence. Fe5(InTe4)3 obeys the Curie–Weiss law at high temperatures with θ=−26.3 K and C=1.60 emu/mole Fe atom, and undergoes a transition to a spin glass state at 6.0 K. The spin glass state has been characterized by an analysis of the field and temperature dependence of the thermal remanent magnetization and isothermal remanent magnetization. The hysteresis loops measured at 2.0 K under field-cooling and zero-field-cooling conditions reveal the presence of a small unidirectional exchange interaction.