% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Kotla:627883,
      author       = {Kotla, Surya Rohith and Ramakrishnan, Sitaram and Schaller,
                      Achim M. and Rekis, Toms and Eisele, Claudio and Bao, Jin-Ke
                      and Noohinejad, Leila and de Laitre, Geoffroy and de
                      Boissieu, Marc and van Smaalen, Sander},
      title        = {{D}eciphering the commensurately modulated monoclinic phase
                      of {R}b$_2${Z}n{C}l$_4$ at low temperatures},
      journal      = {Journal of solid state chemistry},
      volume       = {345},
      issn         = {0022-4596},
      address      = {Orlando, Fla.},
      publisher    = {Academic Press},
      reportid     = {PUBDB-2025-01658},
      pages        = {125226},
      year         = {2025},
      abstract     = {The ferroelectric phase III of Rb$_2$ZnCl$_4$ is stable
                      below $T_c$ = 192 K. It is known to be a threefold
                      superstructure of the centrosymmetric high-temperature
                      structure, with space group $P2_1 cn$. Below $T_L$ = 70 K,
                      phase IV exists as a sixfold superstructure. We report the
                      crystal structure of phase IV with monoclinic symmetry $Cc$
                      (b unique), while a structure model with symmetry $Pn$ (c
                      unique) leads to an almost equally good, yet significantly
                      worse fit to the diffraction data. Employing the superspace
                      approach to these commensurately modulated structures
                      results in modulation waves that follow the two-dimensional
                      irreducible representation $T_1$ of $P2_1 cn$, albeit with
                      different order parameter directions defining $Cc$ and $Pn$
                      symmetries, consistent with the literature. Standard tools
                      of crystal-chemical analysis indicate that the sixfold
                      superstructure is more stable than the threefold
                      superstructure of phase III. However, crystal-chemical
                      arguments cannot distinguish between the correct
                      superstructure model with space group $Cc$ ($b$ unique) and
                      the incorrect superstructure model with symmetry $Pn$ ($c$
                      unique) for phase IV. New crystal chemical tools are
                      required, in order to attain a meaningful understanding of
                      superstructure formation.},
      cin          = {FS DOOR-User / FS-PET-D},
      ddc          = {540},
      cid          = {$I:(DE-H253)FS_DOOR-User-20241023$ /
                      I:(DE-H253)FS-PET-D-20190712},
      pnm          = {631 - Matter – Dynamics, Mechanisms and Control
                      (POF4-631) / 6G3 - PETRA III (DESY) (POF4-6G3) /
                      FS-Proposal: I-20190544 (I-20190544) / DFG project
                      G:(GEPRIS)406658237 - Aperiodische Kristalle: Struktur,
                      Dynamik und elektronische Eigenschaften (406658237)},
      pid          = {G:(DE-HGF)POF4-631 / G:(DE-HGF)POF4-6G3 /
                      G:(DE-H253)I-20190544 / G:(GEPRIS)406658237},
      experiment   = {EXP:(DE-H253)P-P24-20150101},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:001425621500001},
      doi          = {10.1016/j.jssc.2025.125226},
      url          = {https://bib-pubdb1.desy.de/record/627883},
}