%0 Journal Article
%A Grzechnik, A.
%A Friese, K.
%T Crystal structures and stability of NaLnF4 (Ln = La, Ce, Pr, Nd, Sm and Gd) studied with synchrotron single-crystal and powder diffraction
%J Dalton transactions
%V 41
%@ 1477-9226
%C London
%I Soc.
%M PreJuSER-111852
%P 10258 - 10266
%D 2012
%Z Record converted from VDB: 16.11.2012
%X Crystal structures of the NaLnF(4) materials (Ln = La, Ce, Pr, Nd, Sm or Gd) were studied with synchrotron single-crystal and powder diffraction. The materials with Ln = La, Ce, Nd, Sm and Gd have the average β structure (P6, Z = 1) with partial ordering of the cations. A new type of a superstructure due to ordering of the cations and vacancies was found in NaPrF(4) (P3, Z = 6). It could be described using the group-subgroup relationships P6↔P3. Our observations suggest that the β structure is unstable and that the ordering is a slow process at ambient conditions. Upon compression, β-NaNdF(4), β-NaGdF(4) and the superstructure NaPrF(4) are stable to at least 8 GPa with no evidence for any pressure-induced disorder-order phenomena.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:22797523
%U <Go to ISI:>//WOS:000307306400020
%R 10.1039/c2dt30650f
%U https://juser.fz-juelich.de/record/111852