Magnetic and magnetoresistive properties of the series Ce(Ni 1- xCo x) 2B 2C

Abstract

Structural, magnetic, calorimetric and magnetoresistive studies on the solid solution Ce(Ni 1- x Co x ) 2B 2C demonstrate that the Co-substitution decreases the unit-cell volume, the Sommerfeld constant γ, and the Pauli susceptibility χ 0. It increases the Debye temperature and the strength of the crystalline electric field. The structural modification can be related to the variation of the tetrahedral angle subtended by the B-(Ni, Co)-B bonds: a decrease in the tetrahedral angle contracts the parameter a and elongates the length c and vice versa. The variation in the magnetic and electronic properties can be traced down to the shift of E F (predominantly due to the less filling of the 3d-band) away from the peak maximum of the density of state and the consequent reduction of N( E F). The influence of the variation of the band filling and the f-d hybridization on the magnetic behavior of CeT 2B 2C will be considered.