Electronic structure and magnetic properties of

Abstract

Characterized by x-ray powder diffraction is a layered compound isostructural with : a = 3.80 Å; c = 22.19 Å; space group . The magnetic properties are similar to those of but with an even more pronounced difference between the intralayer and interlayer exchange interactions of localized moments. The magnetic susceptibility above 100 K is of a Curie - Weiss nature; the Curie temperature is +250 K. An antiferromagnetic transition with K occurs; in the ordered state, ferromagnetic layers are coupled antiferromagnetically. The analysis showed the intralayer exchange interaction and interlayer exchange interaction to be 16.7 K and -0.06 K, respectively. A band-structure calculation using the LSW method was performed for in the ferromagnetic state (neglecting the interlayer antiferromagnetic ordering). The calculations show that is a semiconductor with a band gap of 0.7 eV. The potassium atoms are nearly ionized. The Cr states are completely spin polarized. The electronic configuration of Cr is , with a local magnetic moment of per Cr atom.