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Monoclinic-orthorhombic phase transitions in A_2BX_4 single crystals with Sr_2GeS_4-type structure

Ferroelectrics Volume 169 Issue 1 Page 149-158
published_at 1995
Title
Monoclinic-orthorhombic phase transitions in A_2BX_4 single crystals with Sr_2GeS_4-type structure
Creators Kasano H.
Creators Kojima M.
Creators Shouji T.
Creators Mashiyama H.
Creator Keywords
X-ray diffraction Sr_2GeS_4-type structure β-K_2SO_4-type structure α-β transition
The structural phase transitions including the monoclinic-orthorhombic transition (α-β transition) in K_2ZnI_4, Rb_2CoI_4 and Rb_2MnI_4 are investigated by means of X-ray diffraction. These compounds take the Sr_2GeS_4-type structure at room temperature. In Rb_2CoI_4 and Rb_2MnI_4, the α-modification is transformed to the β-modification (β-K_2SO_4-type structure) at 515 K and 510 K, respectively. In the β-modification of Rb_2MnI_4, it is found that the transition from the normal phase (space group Pmcn) to incommensurate one (modulation along c^*) takes place at around 520 K. On the other hand, the α-β transition is not observed up to the melting point in K_2ZnI_4. We discuss the α-β transition on the basis of the ratio the ionic radius of A^+ to the average bond length B-X in tetrahedral BX_4^<2-> ion. It is found that the compounds in this family are classified into three types by the ratio.
Languages eng
Resource Type journal article
Publishers Taylor and Francis
Date Issued 1995
File Version Not Applicable (or Unknown)
Access Rights metadata only access
Relations
[ISSN]0015-0193
[NCID]AA00644949
info:doi/10.1080/00150199508217325
[isVersionOf] [URI]http://www.tandf.co.uk/journals/titles/00150193.asp
Schools 大学院理工学研究科(理学)