Person
Gervais Chapuis
Related publications (85)
The luminescence of NaxEu3+(2−x)/3MoO4 scheelites depends on the number of Eu-clusters occurring in their incommensurately modulated structure
Gervais Chapuis, Jean-Claude Bünzli, Alla Arakcheeva, Philip Pattison, Svetlana Eliseeva, Dmitry Logvinovich
Scheelite related compounds with general formula Mn(XO4)m are of interest owing to their optical properties, stability and relatively simple preparation. Eu3+-containing scheelites are considered as red emitting phosphors and the main factors affecting the ...
2012Initiatives in crystallographic education
The rapid development of the Internet has created new opportunities for teaching in general and it is our aim to show how the current evolution can best be exploited for crystallography education in particular. Currently, we can find a very large selection ...
2011Crystal Structure and Optical and Magnetic Properties of Pr2(MoO4)3
Gervais Chapuis, Alla Arakcheeva, Philip Pattison, Dmitry Logvinovich
Praseodymium molybdate Pr2(MoO4)3 was synthesized using the standard ceramic route. The crystal structure of the material has been successfully solved in superspace group I2/b(Rβ0)00 with lattice constants a = 5.30284(4), b = 5.32699(3), c = 11.7935(1)A° , ...
2010The incommensurately modulated structures of natural natrite at 120 and 293 K from synchrotron X-ray data
Gervais Chapuis, Alla Arakcheeva, Philip Pattison
The incommensurately modulated structure of the mineral natrite has been refined for the first time. Two single-crystal grains, Lv and Kh, from two different occurrences [Mt. Karnasurt, Lovozero massif (Lv), Kola peninsula, Russia, and the pegmatite of Mt. ...
Mineralogical Society of America2010David H. Templeton, 1920-2010
Acta Crystallographica Section A: Foundations of Crystallography covers theoretical and fundamental aspects of the structure of matter. The journal is the prime forum for research in diffraction physics and the theory of crystallographic structure determin ...
International Union of Crystallography2010LiZnNb4O11.5: A novel oxygen deficient compound in the Nb-rich part of the Li2O–ZnO–Nb2O5 system
Gervais Chapuis, Alla Arakcheeva, Philip Pattison
A novel lithium zinc niobium oxide LiZnNb4O11.5 (LZNO) has been found in the Nb-rich part of Li2O–ZnO–Nb2O5 system. LZNO, with an original a-PbO2 related structure, has been synthesized by the routine ceramic technique and characterized by X-ray diffractio ...
2010The role of the tangent bundle for symmetry operations and modulated structures
Gervais Chapuis, Kurt Schenk, Philippe Kocian
An equivalence relation on the tangent bundle of a manifold is defined in order to extend a structure (modulated or not) onto it. This extension affords a representation of a structure in any tangent space and that in another tangent space can easily be de ...
2010Validating the model of a (3+1)-dimensional incommensurately modulated structure as generator of a family of compounds for the Eu2(MoO4)3 scheelite structure
Gervais Chapuis, Alla Arakcheeva, Philip Pattison, Jorge Martinez Garcia
The previously proposed model postulating that the incommensurately modulated KNd(MoO) structure can act as a generator of the scheelite family members is validated here by refining the crystal structure of europium molybdate, Eu(MoO). ...
2009The role of silver on the stabilization of the incommensurately modulated structure in calaverite, AuTe2
Gervais Chapuis, Alla Arakcheeva
Structural investigations of several minerals belonging to the calaverite group with composition Au1–xAgxTe2 (x = 0.00, 0.02, 0.05, 0.09, 0.19, and 0.33) indicate that Ag is randomly distributed on the Au sites. This suppresses the valence fluctuation of A ...
Mineralogical Society of America2009Differential geometry: a natural tool for describing symmetry operations
Gervais Chapuis, Kurt Schenk, Philippe Kocian
Differential geometry provides a useful mathematical framework for describing the fundamental concepts in crystallography. The notions of point and associated vector spaces correspond to those of manifold and tangent space at a given point. A space-group o ...
2009