A nuclear magnetic resonance study of gallium single crystals—I

Temperature variation of electric field gradient in α-gallium metal

“…The only two theoretical works on EFG in this metal, which are available in the literature are due to Valic and Williams [1] and Lodge [6]. But all these authors had evaluated only one part, namely, the ionic contribution to EFG.…”

“…But all these authors had evaluated only one part, namely, the ionic contribution to EFG. Valic and Williams, in their work [1], had however, obtained the electronic contribution indirectly by taking the difference of the experimental EFG tensor and the calculated ionic contribution. As the sign of EFG in quadrupole resonance experiment is undetermined, they [1] had estimated the electronic contribution for both the signs of resonance frequency and predicted the sign of the net EFG to be negative.…”

“…Valic and Williams, in their work [1], had however, obtained the electronic contribution indirectly by taking the difference of the experimental EFG tensor and the calculated ionic contribution. As the sign of EFG in quadrupole resonance experiment is undetermined, they [1] had estimated the electronic contribution for both the signs of resonance frequency and predicted the sign of the net EFG to be negative. This prediction has been subsequently confirmed by Segel and Stroud [4] from their analysis of quadrupole anomaly data.…”

“…In a-Ga, the results of q and Z from pure quadrupole resonance experiment are available [1] at three different temperatures. The only two theoretical works on EFG in this metal, which are available in the literature are due to Valic and Williams [1] and Lodge [6].…”

“…While the former has an orthorhombic structure, the latter is monoclinic. Gallium metal in both the phases has been the subject of extensive experimental study [1][2][3][4] in respect of electric quadrupole interaction. One common property they share is that both of them have non-axial symmetry.…”