Nuclear magnetic resonance of⁵¹V (I=⁷/₂) in lanthanide vanadates: II. The nuclear electric quadrupole interaction

For pt.I see ibid., vol.15, p.5275 (1982). Nuclear magnetic resonance of 51 V (I= 7 / 2 ) in the tetragonal zircon structure LnVO 4 of the lanthanide vanadates is used to measure the nuclear electric quadrupole splitting term P(I z 2 - 1 / 3 I(I+1)). Values of mod P/h mod have been determined for all members of the series from Pr 3+ to Lu 3+ except Pm 3+ , but including Y 3+ . The values are found to vary smoothly with the ratio c 0 /a 0 , where c 0 , a 0 are dimensions of the unit crystal cell. A point-charge calculation of the electric field gradient V zz of the lattice gives general agreement with the experimental result that mod P/h mod diminishes as c 0 /a 0 increases. From the value Q=-0.052(10) of Childs (1967), the Sternheimer parameter gamma infinity is found to be -12(3) on the basis that P is positive.