Magnetic properties of bismuth-doped ytterbium and holmium pyrochlore titanates

Bismuth-doped ytterbium and holmium titanates have been synthesized and their magnetic properties have been investigated. The magnetization curves and temperature dependences of the susceptibility in fields of up to 30 kOe at temperatures from 2 to 300 K have been obtained. The properties of the doped and undoped titanates have been compared. It has been established that the temperature dependences of the product of susceptibility and temperature contains a linear portion and the slope sign in these dependences changes upon doping for both the Ho$_{2}$Ti$_{2}$O$_{7}$ and Yb$_{2}$Ti$_{2}$O$_{7}$ titanates. Based on the investigated temperature dependences of the susceptibility, the magnetic dipole and exchange couplings in the titanates have been analyzed.