Electron-nuclear double resonance of Mn2+ in quadratic-layer fluorides. Nuclear quadrupole interaction and zero-point spin deviation

摘要: Abstract The spin-hamiltonian parameters for Mn2+ in K2MgF4, K2ZnF4, K2CdF4, Rb2MgF4, Rb2ZnF4 and Rb2CdF4 have been determined by means of ENDOR experiments at 4.2K. In addition the lattice constants measured, order to enable us study influence small changes distance between fluorine manganese ions on nuclear-quadrupole hyperfine interactions. Calculating electric-field gradients basis a point-charge model, rather accurate description observed interactions is obtained. Also, present results support existence linear relation anisotropy structure coupling proposed earlier. Furthermore it appears that axial crystal-field parameter D not simply proportional terms or quadratic part potential Vax. A relatively value has derived hyperfine-structure constant concentrated K2MnF4 Rb2MnF4. Together with experimental (literature) data A〈S〉 antiferromagnetically ordered state this leads an zero-point spin deviation agrees excellently spin-wave theory. From data, together measurements perovskite fluorides concluded supertransferred interaction along Mn-F-Mn path factor 2.25 (±30) larger than values predicted theoretically Owen et al. Huang