TY - JOUR
T1 - Systematics of c-axis phonons in the thallium- and bismuth-based cuprate superconductors
AU - Tsvetkov, A.A.
AU - Dulic, D.
AU - van der Marel, D.
AU - Damascelli, A.
AU - Kaljushnaia, G.A.
AU - Gorina, J.I.
AU - Senturina, N.N.
AU - Kolesnikov, N.N.
AU - Ren, Z.F.
AU - Wang, J.H.
AU - Menovsky, A.A.
AU - Palstra, T.T.M.
PY - 1999/1/1
Y1 - 1999/1/1
N2 - We present grazing incidence reflectivity measurements in the far-infrared region at temperatures above and below Tc for a series of thallium- (Tl2Ba2CuO6, Tl2Ba2CaCu2O8) and bismuth- (Bi2Sr2CuO6, Bi2Sr2CaCu2O8, and Bi2-xPbxSr2CaCu2O8) based cuprate superconductors. From the spectra, which are dominated by the c-axis phonons, longitudinal optical (LO) frequencies are directly obtained. The reflectivity curves are well fitted by a series of Lorentz oscillators. In this way the transverse optical (TO) phonon frequencies were accurately determined. On the basis of the comparative study of the Bi- and Tl-based cuprates with a different number of CuO2 layers per unit cell, we suggest modifications of the assignment of the main oxygen modes. We compare the LO frequencies in Bi2Sr2CaCu2O8 and Tl2Ba2Ca2Cu3O10 obtained from intrinsic Josephson junction characteristics with our measurements, and explain the discrepancy in LO frequencies obtained by the two different methods.
AB - We present grazing incidence reflectivity measurements in the far-infrared region at temperatures above and below Tc for a series of thallium- (Tl2Ba2CuO6, Tl2Ba2CaCu2O8) and bismuth- (Bi2Sr2CuO6, Bi2Sr2CaCu2O8, and Bi2-xPbxSr2CaCu2O8) based cuprate superconductors. From the spectra, which are dominated by the c-axis phonons, longitudinal optical (LO) frequencies are directly obtained. The reflectivity curves are well fitted by a series of Lorentz oscillators. In this way the transverse optical (TO) phonon frequencies were accurately determined. On the basis of the comparative study of the Bi- and Tl-based cuprates with a different number of CuO2 layers per unit cell, we suggest modifications of the assignment of the main oxygen modes. We compare the LO frequencies in Bi2Sr2CaCu2O8 and Tl2Ba2Ca2Cu3O10 obtained from intrinsic Josephson junction characteristics with our measurements, and explain the discrepancy in LO frequencies obtained by the two different methods.
UR - http://www.scopus.com/inward/record.url?scp=0000653974&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.60.13196
DO - 10.1103/PhysRevB.60.13196
M3 - Article
AN - SCOPUS:0000653974
VL - 60
SP - 13196
EP - 13205
JO - Physical review B: Condensed matter and materials physics
JF - Physical review B: Condensed matter and materials physics
SN - 1098-0121
IS - 18
ER -