Van Vleck Orbit-Lattice Interactions In Laz (Z=P,As,Sb,Bi)
Electron spin relaxation in magnetic insulators has been intensively studied for many years.1–4 The primary relaxation mechanism is phonon modulation of the crystal field of the magnetic ion.1 This orbit-lattice interaction should also be present in magnetic metals.5 However, in metals the magnetic spins can also transfer energy to the lattice by means of their exchange coupling to the conduction electrons. As a consequence in the great majority of metals studied to date, this relaxation mechanism via the conduction electrons dominates the spin relaxation, resulting in a linear dependence of EPR linewidth on temperature at liquid helium temperatures.6,7 In contrast it has been recently shown that8 in some Ce alloys the orbit-lattice interaction is the dominant relaxation mechanism at high temperatures. For this reason, in this paper the Van Vleck orbit-lattice interaction1 will be employed to calculate the relaxation rates of Ce3+ in LaZ (Z = P,As,Sb, and Bi). To the best of our knowledge, this is the first paper attempting to calculate the phonon- induced relaxation time in a metal.
KeywordsElectron Paramagnetic Resonance Conduction Electron Relaxation Rate Crystal Field Exchange Coupling
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