Magnetic phase diagrams of itinerant-electron metamagnetic Lu(Co1-xMx)2 (M=Al and Ga) Laves-phase compounds -: art. no. 134401

Detailed magnetization measurements of Lu(Co1-xMx)(2) (M=Al and Ga) Laves-phase compounds with a high quality of homogeneity in composition have been carried out. A first-order ferromagnetic transition at the Curie temperature T-Cl has been confirmed in Lu(Co1-xAlx)(2) with x=0.094 and 0.095. For these compounds, in addition, a metamagnetic transition from the paramagnetic to the ferromagnetic state above T-Cl is induced by applying external magnetic field. The critical temperature To from the first- to the second-order metamagnetic transition was estimated to be 42 K for Lu(Co0.905Al0.095)(2). The concentration dependence of T-0 of Lu(Co1-xAlx)(2) is not so remarkable. In the higher concentration of x, the ferromagnetic transition is of the second-order-type. The magnetic transitions in Lu(Co(1-x)Gal(x))(2) are quite similar to those in Lu(Co1-xAlx)(2). In contrast with previous experimental results, the established magnetic phase diagrams in the vicinity of the onset of ferromagnetism for Lu(Co1-xMx)(2) are in good agreement with the theoretical phase diagram.