Effects of Ga doping on the phase transitions of V2O3

V2O3 undergoes a first-order metal-insulator transition accompanied by a magnetostructural transition at T-MI similar to 160 K. Here, we report a comprehensive study on gallium-doped (4%) polycrystalline V2O3 by employing various experimental techniques such as synchrotron x-ray diffraction, thermal expansion, Raman spectroscopy, DC magnetization, time-of-flight neutron diffraction, heat capacity, and electrical transport. Our studies show several interesting features related to the structural, magnetic, and electronic phase transitions in Ga-doped sample. Intriguingly, the nonmagnetic doping in V2O3 enhances the Neel temperature by 25 K (T-N = 185 K). Further, we find the decoupling of the structural transition from the magnetic and insulator-insulator transition (T-II similar to 185 K). Raman spectroscopic studies reveal that the structural phase transition begins at T* (= 195 K), which is slightly above T-N or T-II, as evidenced from the softening of E-g mode and the splitting of A(1g) mode. Additionally, the rhombohedral and monoclinic phases coexist in a broad temperature range, and a complete phase transformation to monoclinic phase occurs at 127 K.