JETP Letters: issues online

$The results of measurements of the thermal conductivity к and the resistivity ρ of three different high-rc Bi2Sr2Cu208+), crystals in the ab plane in the temperature range 10-140 К are presented. It was found that 1) the maximum thermal conductivity of the crystals is several times higher than that of previously studied samples; 2) in contrast to the computational results of the theory of electronic heat transport in anisotropic high-Te cuprate crystals, the maximum values of the ratio k(T)Ik{Tc) in Bi2Sr2CaCu208+;y crystals can reach 2, and just as in the less anisotropic YBa2Cu307_x crystals, as this ratio increases, the maximum point of the thermal conductivity shifts in the direction of lower temperatures Tm/Tc^0A; and 3) the maxima on the curves of k(T) are observed in samples with low resistivity ρ and metallic-type conductivity p(T)~T, in which the electronic component ке is comparable in order of magnitude to the total thermal conductivity к at temperatures Гэ=Гс, and in samples whose resistivity increases with decreasing temperature and therefore ке<к. This shows that to explain the appearance of the maxima on the curves к(Т) for high-rc cuprate crystals in the superconducting state, it is necessary to take into account the increase in not only the electronic component of the thermal conductivity ке, as is standard in most modern theoretical calculations, but also in the phonon component кр below Tc. © 1995 American Institute of Physics.$

The results of measurements of the thermal conductivity к and the resistivity ρ of three different high-r_c Bi₂Sr₂Cu₂0₈₊₎, crystals in the ab plane in the temperature range 10-140 К are presented. It was found that 1) the maximum thermal conductivity of the crystals is several times higher than that of previously studied samples; 2) in contrast to the computational results of the theory of electronic heat transport in anisotropic high-T_e cuprate crystals, the maximum values of the ratio k(T)Ik{T_c) in Bi₂Sr₂CaCu₂0_8+;y crystals can reach 2, and just as in the less anisotropic YBa₂Cu₃07__x crystals, as this ratio increases, the maximum point of the thermal conductivity shifts in the direction of lower temperatures T_m/T_c^0A; and 3) the maxima on the curves of k(T) are observed in samples with low resistivity ρ and metallic-type conductivity p(T)~T, in which the electronic component к_е is comparable in order of magnitude to the total thermal conductivity к at temperatures Гэ=Г_с, and in samples whose resistivity increases with decreasing temperature and therefore к_е<к. This shows that to explain the appearance of the maxima on the curves к(Т) for high-r_c cuprate crystals in the superconducting state, it is necessary to take into account the increase in not only the electronic component of the thermal conductivity к_е, as is standard in most modern theoretical calculations, but also in the phonon component к_р below T_c. © 1995 American Institute of Physics.