A STUDY OF RAMAN-SCATTERING AND INFRARED-ABSORPTION SPECTRUM IN A NEWSERIES OF MERCURY-BASED HIGH-T-C SUPERCONDUCTOR (HG,MO)SR-2(Y1-XCAX)CU2O6+DELTA

Lattice vibrations of the (Hg,Mo)Sr-2 (Y-1-x Ca-x)Cu2O6+delta - a new series of mercury-based high-if, superconductor are analyzed with the aid of group theory. The vibrations of species are given. They are 4A( 1g) + B-1g + 5E(g) + 7A(2u) + B-2u + 8E(u). The 4A(1g), B-1g and 5E(g) modes are Raman active, the 6A(2u) and 7E(u) are infrared active. Pho non vibration characteristics of the samples are studied using Raman s cattering and infrared absorption spectra. The experimental results sh ow that the typical phonon vibrational modes appear mainly at 145, 320 , 440, 578, 592 and 645 cm(-1) The intensities of the 145, 320, 440, 5 78 and 645 peaks decrease with increasing Ca content a: and the positi on of 645 peak moves to higher wavenumber slightly. In this article, t he phonon modes are assigned and their variation behavior with increas ing Ca content x are discussed.