485 / 2019-03-18 15:19:34

Functional oxide materials under high pressure

diamond anvil cell, high pressure, functional oxide

全体主题 > High Pressure Physics and Materials Science

Functional oxides are important material systems, which have excellent thermal stability and unique physical properties. These advantages benefit the realistic application of oxide based electronic devices.
We have worked on oxide materials by studying their physical properties under extreme conditions, such as low temperature, high magnetic field and high pressure. Here, we are going to introduce some of the high-pressure study on functional oxide materials carried out in our group.
1) Perovskite oxide and its structural flexibility under high pressure
Perovskite is a prevailing structure model, which includes magnetic manganites, nature minerals, artificial oxide materials, etc. Understanding the structural behavior in perovskite materials is the key to reveal the mechanism of their unique properties. In this work, we find that YAlO3 doesn’t have a first order phase transition but undergoes an isostructural phase transition via the distortion of octahedral AlO6. This work shows that perovskite materials have strong structural flexibility, which could help to achieve new physical states.
2) Enhanced photoluminescence emission in Er:GdVO4 laser crystal
Generally, Er3+ is not sensitive to crystal field. However, by using diamond anvil cell, we managed to enhance the PL effect in Er:GdVO4 laser crystal (both green and red emission bands were enhanced) and a structural phase transition occurred when the enhancement effect present. The high pressure phase can be kept when the pressure is fully released, which helps to search new host materials for Er3+ based laser crystal with better performance.
3) High pressure polymorphs and amorphization of upconversion host material NaY(WO4)2
Obtaining an amorphous phase is very important and it can work as a comparative system to understand the crystal field effect, which is beneficial to design new host materials for optic crystal. Here, we found that high pressure method can be an effective way to obtain amorphous NaY(WO4)2, which is a typical host material for upconversion.