DOUBLE JOSEPHSON PLASMA RESONANCE IN T-ASTERISK PHASE SMLA1-XSRXCUO4-DELTA

Far-infrared sphere resonance in T-phase SmLa0.8Sr0.2CuO4-delta powde r samples is measured down to 7 cm(-1). Below T-c, two peaks are obser ved at 11 and 30 cm(-1) for delta = 0.05. Based on a comparison with t he ...S/I/S/I'/S/I/S/I'/S... /superconductor/insulator2/superconductor ...)-type Josephson junction array model discussed by van der Marel an d Tsvetkov [(Czech. J. Phys. 46, 3165 (1996)], these peaks are attribu ted to the Josephson plasma resonances of the intrinsic Josephson junc tions at the fluorite-type Sm2O2 block layer and the rocksalt-type (La ,Sr)(2)O2-delta block layer, respectively. The relation between the mu ltiple Josephson plasma and the crystal structure of high-T-c cuprates is also discussed.