Effect of pH of Precursor on Up/Downconversion and Cathodoluminescence of Gd2O3:Ho3+/Yb3+ Phosphor and Magneto-Optic Studies

The effect of pH of precursor solution has studied on structural and up/downconversion emission properties of Ho3+/Yb3+ doped Gd2O3 host synthesized through hydrothermal route. Best sample morphology (rod-shaped) is found corresponding to the pH value of pH-9.1 of the precursor solution. Due to the low phonon frequency of Gd2O3 host, intense green upconversion emission around 539, 550nm wavelength is observed from the sample on 980nm diode laser excitation. In down conversion emission mode, bands around 539, 550nm and 653nm are found on 449nm arc lamp excitation. The prepared samples were further studied for cathodoluminescence and the effect of magnetic field on the upconversion emission. The sample has also shown optical bi-stability in upconversion emission when the magnetic field was increased from zero to 1.05x10(4) Oe and then decreased to zero.