NORMAL STATE AND SUPERCONDUCTING PROPERTIES OF BI2SR2CA1-XHOXCU2OY COMPOUNDS

A series of compounds of the type Bi2Sr2Ca1-xHoxCu2Oy (0 less-than-or-equal-to x less-than-or-equal-to 1) were prepared by solid state reaction technique. The x-ray diffraction data showed single phase nature of all the samples. The c-lattice parameter and the volume of the unit cell decrease with x. The transition temperature as found from electrical resistivity and magnetic susceptibility measurements increases from 74K for x = 0 to 80K for x = 0.2 and decreases thereafter. The samples show a semiconducting behaviour for x > 0.5. The critical current density as found from magnetisation measurements is seen to decrease with increasing Ho content. The thermopower is negative for x = 0 at 250K but becomes positive for x = 0.2.