  The structure and magnetic properties of Mn1+xV2-xO4 (0<x<=1), a complex
frustrated system, were investigated by heat capacity, magnetization, x-ray
diffraction, and neutron diffraction measurements. For x<=0.3, a
cubic-to-tetragonal (c > a) phase transition was observed. For x > 0.3, the
system maintained the tetragonal lattice. The collinear and noncollinear
magnetic transition was also observed for all compositions. To reveal the
dynamics of the ground state, first principle simulation was applied to not
only analyze the orbital effects of Mn2+, Mn3+, and V3+ ions, but also the
related exchange energies.
