Spin-spin interaction and the EPR spectrum of KDy(WO4)2

Abstract

The EPR spectrum of a KDy(WO4)2 monoclinic crystal is investigated. It is found that the EPR spectrum of magnetically concentrated materials at a low frequency (9.2 GHz) undergoes a substantial transformation in addition to the well-known broadening of the EPR lines. At low Dy3+ concentrations (x<10−2), the EPR spectrum of an isomorphic crystal, namely, KY(1−x)Dyx(WO4)2, is characterized by the parameters g x=0, g y=1.54, and g z=14.6. For a magnetically concentrated crystal KDy(WO4)2, the g values are as follows: g x=0, g y=0.82, and g z=2.52. It is demonstrated that the difference in the parameters is associated with the specific spin-spin interaction between Dy3+ ions, including the Dzyaloshinski interaction, which is not observed at high frequencies.