Study of Fluorine Hyperfine Interactions in KZnF₃ : V²⁺ and Cr³⁺ by ENDOR

Abstract

Fluorine ENDOR measurements have been made on first and second fluorine neighbours to V²⁺ and Cr³⁺ in KZnF₃ in order to clarify the role of the intervening Zn²⁺ ions. The isotropic hf interaction parameters for the second fluorine neighbours have been obtained as +79 kHz and −22 kHz for V²⁺ and Cr³⁺ respectively. The negative sign of the result for the Cr³⁺ strongly suggests that the cation-cation charge transfer interaction between the 3d³ impurity and Zn²⁺ ions can play important roles in these systems. Differences between the KMgF₃ and KZnF₃ for both V²⁺ and Cr³⁺ are discussed from the same standpoint.