ELECTRON AND NUCLEAR MAGNETIC-RELAXATION IN LA2CUO4 AND RELATED CUPRATES

The nuclear-magnetic-resonance spin-lattice relaxation time (T1) and electron-paramagnetic-resonance (EPR) linewidth ("ss) are calculated for La2CuO4. The large broadening of the EPR at room temperature is shown to narrow with increasing temperature as (3/4/a)3, where 1/4 is the two-dimensional spin-correlation length and a is the lattice constant. The NMR T1 at first lengthens with increasing temperature as (3/4/a)-1, then shortens above T1/4J/2, where J is the in-plane exchange coupling. Explicit values are calculated for T1 and "s2. AE © 1990 The American Physical Society.