Anomalous variation of electric field gradient in α‐Tiα‐Ti

Variation of electric field gradient (EFG) at 181Ta occupying substitutional sites in α‐Tiα‐Ti matrix has been studied in the temperature interval from 10 to 300 K using time differential perturbed angular correlation spectroscopy. Among the main sources of EFG such as conduction electrons and lattice ions, the present study shows that in α‐Tiα‐Ti, the temperature dependence of EFG is predominantly due to conduction electrons. The variation of EFG could not be fitted with either as the linear dependence of temperature (T) or T3/2 over the whole temperature interval 10–300 K. Existence of two different slopes with a change of slope occurring around 150 K is observed while the EFG is fitted with T or T3/2. The above change of slopes of EFG in α‐Tiα‐Ti, which is understood to be due to a slight modification in conduction electron–phonon interactions based on this work, is possibly caused by the electronic topological transitions below 150 K as has been reported.