High pressure electrical transport behavior in SrF ₂ nanoplates

Abstract

The charge transport behavior of strontium fluoride nanocrystals has been investigated by in situ impedance measurement up to 35 GPa. It was found that the parameters changed discontinuously at each phase transition. The charge carriers in SrF 2 nanocrystals include both F − ions and electrons. In the Fm3m phase, pressure makes the electronic transport easier, while makes it more difficult in the Pnma phase. The defects at grain boundaries dominate the electronic transport process. Pressure could make the charge-discharge processes in the Fm3m phase much easier, but make it more difficult in the Pnma phase.

Ionic Transportation and Dielectric Properties of YF3:Eu3+ Nanocrystals

“…The synthetic process of YF 3 :Eu 3+ nanocrystal is similar to that of alkaline earth fluorides [23,24,25,26]. The mixed solution of oleic acid, ethanol and ammonia was stirred for 10 min; then 3.0641 g Y(NO 3 ) 3 ·6H 2 O and 0.7402 g NH 4 F were added and stirred thoroughly.…”

Crystal structures and electronic properties of solid fluorine under high pressure

“…As an all-important dimension independent of temperature and chemical compositions, pressure can effectively change the internal structures and properties of materials, and then form high pressure structures with new physical properties or new matters that cannot exist at ambient pressure. Actually, pressureinduced transitions such as insulator to metal, [2][3][4][5][6][7][8][9] metal to semiconductor, [10] metal to insulator [11][12][13] transitions, have been widely reported in a variety of elements and compounds. Metallic hydrogen was predicted to be a superconductor with a high transition temperature according to Ashcroft [14] in 1968.…”

The Electric and Dielectric Properties of SrF2:Tb3+ Nanocrystals Revealed by AC Impedance Spectroscopy

“…It can be seen that the shape of Tb-doped spectra is similar to that of un-doped result. According to our previous analysis process [23,24], the charge carriers includes both electron and ion; all the spectra were simulated by the equivalent circuit as the inset of Figure 4. The grain and grain boundary resistances of SrF 2 nanocrystals with different Tb doping concentrations were obtained and shown in Figure 5.…”