Thermal conductivity of YBa<inf>2</inf>Cu<inf>3</inf>O<inf>7</inf> from 7 K to 260 K

Thermal conductivity of YBa2Cu3O7 has been measured on samples of a few mm thickness. Above Tc thermal conductivity is found to decrease with increase in temperature, pointing towards a contribution to thermal resistivity from three-phonon Umklapp processes. Below Tc thermal conductivity increases rapidly before reaching a maximum at about 50 K and then falls towards zero at lower temperatures. The experimental set up is described and results discussed. © 1992, the Indian Academy of Sciences. All rights reserved.