Магнитные свойства Rb-=SUB=-2-=/SUB=-KFeF-=SUB=-6-=/SUB=-

Abstract

The static magnetic properties of the Rb2KFeF6 single crystal in the temperature range T=1.8-300 K in magnetic fields H up to 90 kOe are investigated. At T>1.8 K the crystal is not magnetically ordered, however, the behavior of the inverse susceptibility chi-1(T) indicates a negative paramagnetic Curie temperature Theta of ~0.8 K. This is consistent with the analysis of the magnetization curve M(H) by replacing the external field with an effective Heff field with a negative molecular field constant.