The 4th International Conference on Matter and Radiation at Extremes (ICMRE 2019)

425 / 2019-03-12 21:11:54

The Structure Change of Ca2N with Different Medium under High Pressure

Ca2N; high pressure; pressure medium; structural transform

Plenary track > High Pressure Physics and Materials Science

Ca2N was identified as two-dimensional layered electirde that composed of cationic layers and anion electrons confined in a two-dimensional space. The excess electrons between the layers behave as the anion electrons. Due to the larger space inter-Ca2N layer, Ca2N is successful exfoliated into monolayer or multilayers. This feature greatly expands the technological applications of electrides in batteries, electronics, catalysis, and effective electron donor in chemical reactions. The layer spacing decreases with the increase of the pressure, and thus affect its electron behavior. Our previous work reveals that under compression, Ca2N undergoes structural transforms with unprecedented transitions of metal to semiconductor. But there was no pressure medium used before. In order to explore the effect of phase change and layer structure under compression, we load different pressure medium (He, Ne, Ar, N2) in a diamond anvil cell (DAC). The results show that transformation pressure of Ca2N varies in different gas environments. The order of Ca2N phase transforms pressure is Ar>He>Ne>N2. Laser heating is also carried out under high pressure in order to synthesize new compounds, we find that a new nitride was synthesized after heating with Ca2N and N2 coexist.