Magnetic structure and magnetic properties of the spinel solid solutions ZnCr_2xAl_2-2xS₄(0.85⩽x⩽1). II. Magnetic properties

Abstract

For pt.I see ibid., vol.19, p.1783 (1986). The spinel solid solutions ZnCr2xAl2-2xS4 (0.85<or=x<or=1) have been studied by means of Mossbauer spectroscopy and magnetisation measurements. For the pure compound, several samples (powders and single crystal) have been studied. The existence of the three magnetic phases, determined by neutron diffraction (part I of this study), has been conformed by Mossbauer spectroscopy and the values of the hyperfine parameters are given. The variation of these parameters with temperature shows that the magnetic phase transition at T0 is of first order. No irreversibilities and quasi-isotropical properties are established for the single-crystal magnetisation, due to the existence of the three phases. No true difference occurs when the chromium is diluted by aluminium, in the dilution range studied.