Investigation of the electronic properties of tellurium—nuclear quadrupole interaction

The field gradient at the nuclear sites in tellurium has been studied quantitatively using electronic wave functions obtained from orthogonalized plane-wave (OPW) band calculations reported in the preceding paper and a first-principles treatment of antishielding effects. The major effect of antishielding is felt on the contributions to the field gradient from the plane-wave components of the band wave functions, the effective antishielding factor γ_PW-PW for this contribution being about 25% of γ_∞ for Te⁺⁶ ions, in contrast to about 0.6γ_∞ found for γ_PW-PW in recent work on noncubic metals. The reasons for this difference in nature of γ_PW-PW in the present semiconductor and in metals are discussed. Our theoretical value of the net field gradient at the ¹²⁵Te nuclear sites is -2.70 ×{} 10¹⁶ esu/cm³, in reasonable agreement with recent experimental results which lie in the range -3.10 to -2.07 ×{} 10¹⁶ esu/cm³.