Fabrication and optical properties of transparent LaErZr2O7 ceramic with high excess contents of La and Er

In this study, transparent LaErZr 2 O 7 ceramic with high excess La and Er contents (nominally La 1.28 Er 1.28 Zr 2 O 7.84 ) was successfully prepared by vacuum sintering at 1850 °C for 6 h using nanosized powder. The XRD , SEM, EDX and TEM results reveal that the single pyrochlore phase in the powder sample transforms to the coexistence of La-rich pyrochlore phase and Er-rich defect fluorite phase after high temperature sintering . The high excess amounts of La and Er favor the formation of pyrochlore structure. Despite the coexistence of two phases, the sample with 1 mm thickness shows excellent in-line transmittance in the visible to mid-infrared region (as high as 81% at 1100 nm). The upconversion and infrared emission under 980 nm exciting were measured and discussed as well.