Mariette Céline, Trzop Elzbieta, Zerdane Serhane, Fertey Pierre, Zhang Daopeng, Valverde-Muñoz Francisco J, Real José Antonio, Collet Eric
Institut de Physique de Rennes, UMR 6251, Univ. Rennes 1, CNRS, Campus de Beaulieu, 35042 Rennes, France.
Synchrotron SOLEIL, BP 48, L'Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette Cedex, France.
Acta Crystallogr B Struct Sci Cryst Eng Mater. 2017 Aug 1;73(Pt 4):660-668. doi: 10.1107/S2052520617007685. Epub 2017 Jul 27.
The complex relaxation from the photoinduced high-spin phase (PIHS) to the low-spin phase of the bimetallic two-dimensional coordination spin-crossover polymer [Fe(Hg(SCN))] is reported. During the thermal relaxation, commensurate and incommensurate spin-state concentration waves (SSCWs) form. However, contrary to the steps forming at thermal equilibrium, associated with long-range SSCW order, the SSCWs forming during the relaxation from the PIHS phase correspond to short-range order, revealed by diffuse X-ray scattering. This is interpreted as resulting from the competition between the two types of SSCW order and another structural symmetry breaking, due to ligand ordering, occurring at low temperature and precluding long-range SSCW order.
报道了双金属二维配位自旋交叉聚合物[Fe(Hg(SCN))]从光诱导高自旋相（PIHS）到低自旋相的复杂弛豫过程。在热弛豫过程中，形成了相称和不相称的自旋态浓度波（SSCWs）。然而，与热平衡时形成的与长程SSCW有序相关的台阶相反，从PIHS相弛豫过程中形成的SSCWs对应于短程有序，这通过漫散射X射线得以揭示。这被解释为是由于两种类型的SSCW有序之间的竞争以及另一种结构对称性破缺（由于配体有序化）导致的，这种破缺发生在低温下并排除了长程SSCW有序。
