Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
Collection

toTop

If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

home > search >

Low temperature phase transition and crystal structure of CsMgPO<sub>4</sub>

Author:
Maria Orlova  Sergey Khainakov  Dmitriy Michailov  Lukas Perfler  Christoph Langes  Volker Kahlenberg  Albina Orlova  


Journal:
Journal of Solid State Chemistry


Issue Date:
2015


Abstract(summary):

Abstract CsMgPO 4 doped with radioisotopes is a promising compound for usage as a radioactive medical source. However, a low temperature phase transition at temperatures close to ambient conditions (~−40 °C) was observed. Information about such kind of structural changes is important in order to understand whether it can cause any problem for medical use of this compound. The phase transition has been investigated in detail using synchrotron powder diffraction, Raman spectroscopy and DFT calculations. The structure undergoes a transformation from an orthorhombic modification, space group Pnma (RT phase) to a monoclinic polymorph, space group P 2 1 / n (LT phase). New LT modification adopts similar to RT but slightly distorted unit cell: a =9.58199(2) Å, b =8.95501(1) Å, c =5.50344(2) Å, β =90.68583(1)°, V =472.198(3) Å 3 . CsMgPO 4 belongs to the group of framework compounds and is made up of strictly alternating MgO 4 - and PO 4 -tetrahedra sharing vertices. The cesium counter cations are located in the resulting channel-like cavities. Upon the transformation a combined tilting of the tetrahedra is observed. A comparison with other phase transitions in ABW-type framework compounds is given. Graphical abstract Structural behavior of β - tridymite-type phosphate CsMgPO 4 , considered as potential chemical form for radioactive Cs-source has been studied at near ambient temperatures. A phase transition at (~−40 °C) has been found and investigated. It has been established that the known orthorhombic RT modification, space group Pnma , adopts a monoclinic cell with space group P 2 1 / n at low temperatures. In this paper, we present results of structural analysis of changes accompanying this phase transition and discuss its possible impact on the application properties. Highlights • β-Tridymite type phosphate CsMgPO 4 undergoes so called translationengleiche phase transition of index 2 at −40 °C. • The structure transforms from an orthorhombic (space group Pnma ) to a monoclinic (space group P 2 1 / n ) phase. • In comparison with the RT form, the LT modification adopts a similar but slightly distorted unit cell.


Page:
224-224


Similar Literature

Submit Feedback

This function is a member function, members do not limit the number of downloads