Spin-cluster excitations in the rare-earth kagome system N d 3 G a 5 Si O 14

摘要: Spin-cluster excitations induced by microwave radiation have been detected as a function of an applied magnetic field in the rare-earth kagome system $\mathrm{N}{\mathrm{d}}_{3}\mathrm{G}{\mathrm{a}}_{5}\mathrm{Si}{\mathrm{O}}_{14}$. The results are interpreted using Heisenberg model which allows for anisotropic exchange interactions between neighboring spins. At frequency 120 GHz conventional independent-ion electron spin resonance (ESR) spectrum, due to Zeeman splitting ground state Kramers doublet, is not observed at low temperatures. Instead, large number resonances seen that shifted from ESR position. These persist temperatures well above 20 K with similar behavior found 230 GHz. observations consistent excitation waves short-range antiferromagnetically correlated loops or clusters and spectral features previously $\mathrm{P}{\mathrm{r}}_{3}\mathrm{G}{\mathrm{a}}_{5}\mathrm{Si}{\mathrm{O}}_{14}$ system. Upon increasing temperature and/or frequency, broad does eventually emerge predicted doublet field.