First polycrystalline magneto-optical transparent Pr2Zr2O7 pyrochlore ceramic for Faraday rotation

To design an innovative magneto-optical material aimed at a large Verdet constant coincides with the development trend of state-of-the-art modern optical devices. In this work, a new magneto-optical transparent Pr2Zr2O7 ceramic with pyrochlore structure, for the first time, was successfully fabricated by vacuum sintering plus hydrogen reduction. The two- and three-dimensional images observed on the laser scanning confocal microscopy reveal that the grain-boundary dent depth of the polished Pr2Zr2O7 ceramic is only ~1.6 μm upon thermal etching at a high temperature of 1675 °C for 2 h, owing to its excellent heat-resistance ability. The crystal-clear Pr2Zr2O7 ceramic has a high in-line transmittance of ~71.6% at 780 nm (~92.3% of the ideal Pr2Zr2O7 single crystal), a high refractive index of ~2.1, and an effective magnetic moment of ~5.28 μB. In the visible region, the O2− polarizability and optical basicity of the Pr2Zr2O7 compound generally retain constants around 2.37 ± 0.07 Å3 and 0.965 ± 0.015, respectively. The magneto-optical transparent Pr2Zr2O7 ceramic has high Verdet constants of -336 ± 4, -208 ± 3, -108 ± 1, and -48 ± 2 rad·T-1·m-1 at 515, 635, 780, and 1064 nm, respectively, which were ~1.55-fold higher than the commercial Tb3Ga5O12 single crystal. Our developed new-type ceramic material possesses excellent potential application for Faraday rotation.