Va. Atsarkin et al., Anomalies of the electronic spin-lattice relaxation of Gd3+ in YBa2Cu4O8 and YBa2Cu3O6+x near 200 K, JETP LETTER, 69(8), 1999, pp. 610-615
A sharp kink in the temperature dependence of the electronic spin-lattice r
elaxation rate near 200 K was found in the high-temperature superconductors
YBa2Cu4O8 and YBa2Cu3O6+x. The effect is correlated with opening of a spin
gap and microscopic phase separation. (C) 1999 American Institute of Physi
cs. [S0021-3640(99)00808-7].