Floating zone growth and optical phonon behavior of corundum Mg₄Ta₂O₉ single crystals

Abstract

We demonstrate that corundum Mg4Ta2O9 crystals, free of low-angle grain boundaries and bubbles, were prepared for the first time by the infrared heating optical floating zone method.

Photoluminescence in wide band gap corundum Mg4Ta2O9 single crystals*

“…All the Raman peaks in the spectra can be assigned to in the whole wavenumber range. [23,33] In the Y (ZZ)-Y configuration (Fig. 4(a)), the spectrum is dominated by A 1g 083301-3 model at 820 cm −1 and all other six A 1g models at 200 cm −1 , 250 cm −1 , 320 cm −1 , 361 cm −1 , 454 cm −1 , and 639 cm −1 are achieved properly.…”

“…The lower blueshift speed of regular B bond should be due to the phonons at 820 cm −1 having a lower thermal response. [23]…”

“…And the structure and orientation of the as-grown crystals were identified previously. [23] The absorption and transmission spectra were measured via Shimadzu UV-VIS-3600 spectrophotometer at roomtemperature. Both the PL spectra and polarized Raman spectra measurements were performed by the Jobin Yvon High Resolution 800 Raman spectrometer in the backscattering geometry with polarized plate, half wave plate, the 514.5-nm excitation line from the Spectra Physics Stabilize 2017 Ar ion laser and Linkam THS600 Thermal stage.…”

“…[21,22] Previously, high-quality corundum Mg 4 Ta 2 O 9 single crystals have been achieved by the optical floating zone method. [23] In this work, we investigate the experimental band gap energy and strong near-infrared (NR) emission from corundum Mg 4 Ta 2 O 9 , which may open the door for a large number of potential applications in many fields including laser diodes, NR light-emitting devices (NRLEDs), etc.…”

The Raman scattering of trirutile structure MgTa2O6 single crystals grown by the optical floating zone method

“…Based on our previous experience with the growth of this series of crystals, 15,16 the MgTa 2 O 6 crystals were grown in an air atmosphere. Aer the optimization of the growth parameters, including the growth speed, rotation speed and lamp power, the MgTa 2 O 6 crystals were successfully grown with several large domains.…”