Internal Magnetic Field at the La Atom in La₂MO₄ (M=Cu, Ni)

抄録

A cluster model calculation in which a tight binding Hamiltonian including intraatomic electron electron interaction is exactly diagonalized is carried out to explain the observed values of the internal magnetic fields at the La site in La₂CuO₄ and La₂NiO₄ which are about 1 kOe and about 18 kOe, respectively. It is shown that the internal fields reflect the spin correlation between apical oxygen and Cu or Ni, and that the electron correlation is important to determine the magnitude of the field.