Impact of Growth Environment on the Crystal Growth and Magnetic and Electronic Properties of Ba₂NiWO₆ Single Crystals

This study introduces the effect of growth atmosphere and pressure on the as-grown crystals and the physical characterization of the double perovskite compound Ba₂NiWO₆ (BNWO). The Ni²⁺ ions form a face-centered cubic (FCC) lattice with an ideal octahedral arrangement. Our growth trials by the floating zone method revealed that BNWO exhibits two distinct colors depending on the growth atmosphere, suggesting that it influences its stoichiometry and phase purity. The antiferromagnetic properties of BNWO align with conventional antiferromagnetic behavior with a J = 1 ground state, as determined by entropy calculation. Additionally, surface photovoltage (SPV) spectroscopy indicates that the impurity levels within the crystal influence the electronic properties of BNWO.