Crystal field effects on the magnetic behavior of Yb2V2O7 and Tm2V2O7

The bulk magnetic behaviors of the pyrochlores Yb2V2O7 and Tm2V2O7 were investigated. Calculated susceptibilities were adjusted to obtain the best fit to experimental data. A cubic crystal field Hamiltonian was used with B°4 = −0.633 and B°6 = 0.000705 K for Yb3+ and B°4 = 0.0297 and B°6 = 0.000339 K for Tm3+. The calculated susceptibility for Yb3+ was found to be insensitive to the addition of an axial B°2 parameter to the cubic Hamiltonian.