Getting more out of an incommensurately modulated structure: the example of K5Yb(MoO4)4.
نویسندگان
چکیده
A method based on the superspace approach is presented with the aim of generating a family of modular structures from a single incommensurately modulated structure. This approach based on the variation of the modulation vector q is applied to the generation of the K5Yb(MoO4)4, potassium ytterbium tetramolybdate, family of modular structures. The beta coefficient of the modulation vector q = betab* is a temperature-dependent variable which determines the modification. Our method gives a unified frame to describe and explain the three temperature-dependent phases of K5Yb(MoO4)4. Phase beta can be represented as a polytypic modification with 1/2b* < or = q < or = 2/3b*; phases gamma (q = 1/2b*) and alpha (q = 1b*) are the lowest and the highest temperature members of the K5Yb(MoO4)4 family, respectively.
منابع مشابه
The role of second coordination-sphere interactions in incommensurately modulated structures, using beta-K5Yb(MoO4)4 as an example.
The incommensurate palmierite-like structure of beta-K5Yb(MoO4)4, potassium ytterbium tetramolydate, has been refined in the (3 + 1)-dimensional monoclinic superspace group X2/m(0rho0)00, with X = [0 0 0 0; (1/2) (1/2) 0 0; 0 0 (1/2) (1/2); (1/2) (1/2) (1/2) (1/2)] and the unit-cell parameters a = 10.4054 (16), b = 6.1157 (12), c = 19.7751 (18) A, beta = 136.625 (10) degrees ; q = 0.6354 (30)b*...
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ورودعنوان ژورنال:
- Acta crystallographica. Section B, Structural science
دوره 62 Pt 1 شماره
صفحات -
تاریخ انتشار 2006