  We report a systematic enhancement of the pressure dependence of TN in
A2+[V2]O4 spinels as the V-V separation approaches the critical separation for
a transition to itinerant-electron behavior. An intermediate phase between
localized and itinerant electron behavior is identified in Zn[V2]O4 and
Mg[V2]O4 exhibiting mobile holes as large polarons. In Zn[V2]O4, cooperative
ordering of V-V pairs below a Ts=TN does not totally suppress the V3+-ion spins
at ambient pressure, but makes TN to decrease with pressure. Our results
demonstrate that Zn[V2]O4 and Mg[V2]O4 are less localized than previously
thought.
