Structure of the modulation in thiourea. II. Structure refinement
作者： T. Simonson , F. Dénoyer , R. Currat , C. Vettier
DOI: 10.1051/JPHYS:01988004903047100
关键词: Diffraction 、 Landau theory 、 Crystallography 、 Phase (waves) 、 Crystal structure 、 Superspace 、 Neutron diffraction 、 Amplitude 、 Atomic physics 、 Physics 、 Harmonics 、 General Engineering
摘要: We describe structure refinement of the long-period, commensurate, q=b*/9 phase thiourea, using neutron diffraction data and model derived in a previous paper. The primary distorsion wave two harmonics are taken into account fitted to 660 fundamental satellite reflections. displacive modulation is mainly sinusoidal rotation around b axis (R =0.116 rad) translation along c (T=0.03 c), with small longitudinal non-sinusoidal components. Amplitudes three |Q 3q |∼|Q q |/10; |/100≤|Q 2q | Description de l'affinement la commensurable thiouree, partir donnees neutrons et du modele decrit dans un article anterieur. Comparaison l'information fournie par le developpement Landau l'energie libre avec description les groupes superespace
sci-hub.st 参考文章(5)
Yoichi Shiozaki, Satellite X-ray scattering and structural modulation of thiourea Ferroelectrics. ,vol. 2, pp. 245- 260 ,(1971) , 10.1080/00150197108234099
Kêitsiro Aizu, Possibility of the Transition from an Incommensurate Phase Having Constant Phase Differences to an Incommensurate Phase Having Varying Phase Differences Journal of the Physical Society of Japan. ,vol. 54, pp. 4213- 4220 ,(1985) , 10.1143/JPSJ.54.4213
Yoshihiro Ishibashi, Hiroyuki Shiba, Successive Phase Transitions in Ferroelectric NaNO2 and SC(NH2)2 Journal of the Physical Society of Japan. ,vol. 45, pp. 409- 413 ,(1978) , 10.1143/JPSJ.45.409
T. Simonson, F. Dénoyer, R. Currat, Structure of the modulation in thiourea. I. symmetry properties Journal de Physique. ,vol. 46, pp. 2187- 2195 ,(1985) , 10.1051/JPHYS:0198500460120218700
De Wolff, The pseudo-symmetry of modulated crystal structures Acta Crystallographica. ,vol. 30, pp. 777- 785 ,(1974)