%0 Journal Article
%A Sazonov, Andrew
%A Hutanu, Vladimir
%A Meven, Martin
%A Roth, Georg
%A Kézsmárki, István
%A Murakawa, Hiroshi
%A Tokura, Yoshinori
%A Náfrádi, Bálint
%T The low-temperature crystal structure of the multiferroic melilite Ca$_{2}$ CoSi$_{2}$ O$_{7}$
%J Acta crystallographica / B
%V 72
%N 1
%@ 2052-5206
%C Oxford [u.a.]
%I Wiley-Blackwell
%M FZJ-2016-06936
%P 126 - 132
%D 2016
%X In the antiferromagnetic ground state, below TN ≃ 5.7 K, Ca2CoSi2O7 exhibits strong magnetoelectric coupling. For a symmetry-consistent theoretical description of this multiferroic phase, precise knowledge of its crystal structure is a prerequisite. Here we report the results of single-crystal neutron diffraction on Ca2CoSi2O7 at temperatures between 10 and 250 K. The low-temperature structure at 10 K was refined assuming twinning in the orthorhombic space group P2(1)2(1)2 with a 3 × 3 × 1 supercell [a = 23.52 (1), b = 23.52 (1), c = 5.030 (3) Å] compared with the high-temperature normal state [tetragonal space group P42(1)m, a = b ≃ 7.86, c ≃ 5.03 Å]. The precise structural parameters of Ca2CoSi2O7 at 10 K are presented and compared with the literature X-ray diffraction results at 130 and 170 K (low-temperature commensurate phase), as well as at ∼ 500 K (high-temperature normal phase).
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000369393100014
%$ pmid:26830804
%R 10.1107/S2052520615023057
%U https://juser.fz-juelich.de/record/824327