Magnetic Properties of Tetragonal Ce1-xLuxB2C2(0 ≤x≤0.31) Compounds

Abstract

Specific heat, dc - and ac -magnetic susceptibility and magnetization measurements were performed on rare earth intermetallic compounds Ce 1- x Lu x B 2 C 2 (0 ≤ x ≤0.31) in order to elucidate the magnetic interaction in CeB 2 C 2 . In the process of the substitution of Ce by Lu in CeB 2 C 2 , the characteristics of magnetic transition change from a first-order transition to a second-order one. Furthermore, the spin-glass phase appears at Lu concentration x =0.31. We suppose that the ferromagnetic (FM) and antiferromagnetic (AFM) interactions compete and nearly cancel out each other in CeB 2 C 2 , and hence that a biquadratic interaction might cause the first-order magnetic transition at T N . The Lu substitution breaks the competition between AFM and FM interactions and brings forth randomness in interactions acting on each Ce moment. The typical spin-glass behavior of x =0.31 originates in this random distribution of magnetic interactions.