An orbital glass state of a nearly metallic spinel, CoV${}_2$O${}_4$

Abstract

Strain, magnetization, and unpolarized and polarized neutron diffraction measurements were performed to study the magnetic and structural properties of spinel CoV${}_2$O${}_4$. Magnetostriction measurements indicate that a subtle distortion of the crystal along the direction of magnetization, $\hat{I}”L/L\sim 10^{-4}$, exists and varies from elongation to contraction in a second order fashion upon cooling. Unpolarized and polarized single-crystal neutron experiments indicate that upon cooling the ferrimagnetic structure changes from collinear to noncollinear at $T\sim 90$ K, where the elongation of the crystal is maximized. These results imply the existence of an orbital glassy state in the nearly metallic frustrated magnet CoV${}_2$O${}_4$.

5 pages, 4 figures