Synthesis and characterization of electric and magnetic properties of the new intermetallic compounds M 3(GaTe 3) 2 (M = Cr, Fe, Co)

Abstract

The new amorphous intermetallic materials, M 3(GaTe 3) 2 (M = Cr, Fe, Co) are prepared by using a rapid precipitation metathesis reaction between the Zintl phase material K 3GaTe 3 and the divalent transition metal halides in aqueous solution. The d.c. specific resistivity measurements of these materials exhibit metallic (M = Fe, Co) and semiconductor (M = Cr) behavior. The magnetic and electrical properties for these materials are examined as a function of temperature, Cr 3(GaTe 3) 2 exhibits antiferromagnetic coupling between localized magnetic moments and highly temperature dependent semiconductivity. Two materials undergo a transition to a spin glass state at low temperature (for M = Fe, T f = 22 K; for M = Co, T f = 2.2 K). Magnetization data are also reported as both thermal remanent magnetization (TRM) and isothermal remanent magnetization (IRM) as a function of magnetizing field and temperature. At a magnetization field of 1 kG and a temperature of 6 K, the Fe 3(GaTe 3) 2 exhibit a photomagnetic response consistent with a disruption of the spin-glass state that results from a series of pulses of ultraviolet radiation.