Study of exchange and dipolar interaction in MCuX₃systems by E.P.R.

Abstract

To cite this article: S.P. Harish (1985) Study of exchange and dipolar interaction in MCuX 3 systems by E.P.R., Molecular Physics, 54:4, 911-925, Compounds of the ABX 3 type (where A = K, NH4, Cs, Rb, B = Cu, Ni, Cr, X = C1, Br, F, I) make an interesting study by the presence of BX6, B 2 X4, B 3 X9, linear chains which also show interesting magnetic properties and crystal structures. Single crystals of KCuC13 , NH4CuC13 , RbCuC13 and CsCuC13, in the polycrystalline state have been studied by E.P.R. measurements. These compounds show simple E.P.R. spectra but have interesting dependences of line widths on temperature and g values. The line width dependence has been shown to arise from unresolved hyperfine and dipolar interactions, confirmed by second moment calculations. The quasi axial nature of the g value has been explained as being due to antiferro-distortive ordering of the Cu 2X6 z-octahedra. The ammonium ion acts as a better exchange pathway than potassium in the two respective crystals. The E.P.R. intensities have a Curie type dependence and has no contribution from the dimeric coppers.