Magnetic properties of ternary gallides of type RNi 4Ga (R=rare earths)

Abstract

The magnetic properties of RNi 4Ga (R=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm and Lu) compounds have been investigated. These compounds form in a hexagonal CaCu 5 type structure with a space group P6/ mmm. Compounds with the magnetic rare earths, R= Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm, undergo a ferromagnetic transition at 5, 17, 20, 19, 12, 3.5, 8 and 6.5 K, respectively. The transition temperatures are smaller compared to their respective parent compounds RNi 5. PrNi 4Ga is paramagnetic down to 2 K. LaNi 4Ga and LuNi 4Ga are Pauli paramagnets. All the compounds show thermomagnetic irreversibility in the magnetically ordered state except GdNi 4Ga.