Growth Of A Single MnCr2O4 Spinel On Ni-25Cr-1.5Mn Alloy By The Rhines Pack Method and Photoelectrochemical And Raman Signatures of MnCr2O4 Spinel

Abstract A single thin MnCr₂O₄ spinel layer was synthesized on a Ni-25Cr-1.5Mn alloy by a fine control of oxygen partial pressure using the Rhines pack method, a technique allowing a fine control of the oxygen partial pressure by an appropriate buffering powder mixture. The spinel was characterized using X-Ray Diffraction, Raman spectroscopy and photoelectrochemistry. The cubic spinel MnCr₂O₄ was formed under the oxygen partial pressure close to 5 x 10–²¹ atm. at 1050°C controlled by the buffering Ni-25Cr/Cr₂O₃ powder mixture. Raman MnCr₂O₄ spectrum is characterized by 5 vibrational modes whereas photoelectrochemical characterization revealed the MnCr₂O₄ band gap measurement at 3.7 eV with a n-type conductivity.