Gd3+-Yb3+ exchange interactions in LiYbxY1-xF4 single crystals

Abstract

The evaluated Gd3+-Yb3+ exchange interactions over the nearest and the next-nearest neighbors in LiYbxY1-1F4 are found to increase in parabolic manner with x, the concentration of Yb3+ ions. The Gd3+-Yb3+ exchange interactions are sensitive to x in the range x equals 0.6-1.0, while they are almost constant in the range x- equals 0.1-0.5. The estimated Gd3+-Yb3+ exchange interaction constants are in the range 0.5-2.8 Ghz for x from 0.1 to 1, respectively. These exchange interaction constants are increased with lowering temperature. The results are comparable to those of estimated using the molecular-field model. The average Gd3+-Yb3+ pari exchange interaction constant is determined to be 0.33 Ghz in paramagnetically diluted LiYbxY1-xF4 crystals.