Abstract
We have obtained infrared phonon spectra of spinel structure vanadium oxide ZnV2O4 over the temperature range 10 K < T < 100 K from reflectivity measurements. When the material undergoes the structural transition at T-s = 51 K each of the four phonon peaks is split into a doublet (eight phonons) and additionally two new phonons appear at omega = 187 and 488 cm(-1). Point group analysis shows that such phonon change is consistent with the crystal symmetry I4(1)/amd at T < T-s. We compare this result against recent theories about the orbital ordering mechanism in tetragonal ZnV2O4.