ON THE MAGNETIC-SUSCEPTIBILITY OF TENORITE

This paper reports a theoretical investigation of the perpendicular ma gnetic susceptibility of a tenorite (CuO) single crystal at absolute z ero temperature. We present formulae for the ground state system energ y taking into account the exchange interactions, the magnetic anisotro py energy, and the Zeeman energy, as well as expressions for the equil ibrium angles. Expressions for the susceptibility tensor components ar e obtained. The magnetic susceptibility along the arbitrary direction in (ac)-plane is a 180 degrees periodic function of the field directio nal angle. The magnitude of the projection of the magnetization vector on the field direction depends on the field intensity by the linear l aw. Pm expression for the flip field is obtained, and a crude numerica l estimate of the susceptibility is given. The correctness of the noti on of a flip field in the molecular field approximation for the anisot ropy energy is discussed. The susceptibility anisotropy is caused by b oth the g-factor anisotropy and the non-Heisenberg-type exchange inter actions. The experimental results are discussed.