Specific heat of well-characterized TiBe2at 0 and 7 T

The low-temperature specific heat at magnetic fields of 0 and 7 T, dc susceptibility, and resistivity data for two samples of Ti${\mathrm{Be}}_{2.00}$ and one sample of Ti${\mathrm{Be}}_{1.94}$ ${\mathrm{O}}_{0.05}$ are presented. The temperature dependence of the low-temperature specific heats of all three samples of Ti${\mathrm{Be}}_2$ is found to include an important $T^3\ln T$ term, confirming that spin fluctuations are present in Ti${\mathrm{Be}}_2$, the first metal besides ${\mathrm{UAl}}_2$ where such a $T^3\ln T$ term has been found. Evidence for a magnetic impurity present in one of the two pure Ti${\mathrm{Be}}_2$ samples is inferred from the measurements and confirmed by the same measurements on the sample with oxygen intentionally added. The impurity is thought to increase the low-temperature susceptibility, shape the resistivity, and cause a 3% decrease of the low-temperature specific heat in a 7-T field at lower temperatures. At higher temperatures in the impure samples, and at all temperatures in the purer sample of Ti${\mathrm{Be}}_2$, there is no change from the zero-field values in the specific heat to ± 1% in a 7-T field, in contradiction to the theoretical prediction of Béal-Monod. These field results are discussed with respect to the recent measurements of the low-temperature specific heats in a field of Pd and Lu${\mathrm{Co}}_2$. Previous low-temperature specific-heat results on Ti${\mathrm{Be}}_{2.06}$ and Ti${\mathrm{Be}}_{1.79}$ ${\mathrm{Cu}}_{0.21}$ are also discussed.