Revealing the Crystallographic Features of High-Oxygen Cobalts YBaCo₄O_8.4 Using Recovery of the Reciprocal Space

The use of a standard methodology of reduction and visualization in primary experimental data processing in the x-ray diffraction study of oxygenated single crystals YBaCoO_{7 + x} ( x = 1,4), topical for routine x-ray diffraction analysis is discussed. Substantiated determination of the parameters of the orthorhombic unit cell of oxygenated crystals revealed their correlation with the parameters of the parental hexagonal YBaCoO_{7 + x} ( x = 0) crystal. Additional crystallographic features undetectable earlier without analysis of the diffraction intensity distribution in reciprocal space are determined. Major oxygen-induced structural changes that occur in the basal plane( where the domains of the orthorhombic phase are formed according to the law of pseudotrigonal non-merohedric twinning) are not attributed to violation of the layer sequence along c axis.

кобальтат иттрия и бария, обратное пространство, сверхструктурные модуляции, немероэдрическое двойникование, yttrium and barium cobaltate, reciprocal space, superstructure modulation, non-merohedric twinning

1. Valldor M., Andersson M. The Structure of the New Compound YBaCo4O7 with a Magnetic Feature / Solid State Sci. 2002. Vol. 4. P. 923 - 931.

2. Valldor M. Syntheses and structures of compounds with YBaCo4O7-type structure / Solid State Sci. 2004. Vol. 6. P. 251 - 266.

3. Козеева Л. П., Подберезская Н. В., Смоленцев А. И. и др. Кристаллическая структура кобальтита LuBaCo4O7 / Журн. структур. химии. 2008. Т. 49. № 6. С. 1108 - 1114.

4. Wong-Ng W., Xie W., Yan Y., et al. Structural and thermoelectric properties of BaRCo4O7 (R = Dy, Ho, Er, Tm, Yb and Lu) / J. Appl. Phys. 2011. Vol. 110. P. 113706-1 - 113706-8.

5. Karppinen M., Yamauchi H., Otani S., et al. Oxygen Nonstoichiometry in YBaCo4O7 + δ: Large Low-Temperature Oxygen Absorption/Desorption Capability / Chem. Mater. 2006. Vol. 18. P. 490 - 494.

6. Kadota S., Karppinen M., Motohashi T., Yamauchi H. R-Site Substitution Effect on the Oxygen-Storage Capability of RBaCo4O7 + δ / Chem. Mater. 2008. Vol. 20. P. 6378 - 6381.

7. Алексеев А. В., Каменева М. Ю., Козеева Л. П. и др. Структурный фазовый переход в кобальтате YBaCo4O7 + x при изменении содержания кислорода по данным рентгеновской дифракции на синхротронном излучении / Известия РАН. Сер. физ. 2013. Т. 77. № 2. С. 173 - 176.

8. Chmaissem O., Zheng H., Hug A., et al. Formation of Co3+ octahedra and tetrahedra in YBaCo4O8.1 / J. Solid State. Chem. 2008. Vol. 181. P. 664 - 672.

9. Jia Y., Jiang H., Valkeapää M., et al. Oxygen Ordering and Mobility in YBaCo4O7 + δ / J. Am. Chem. Soc. 2009. Vol. 131. P. 4880 - 4883.

10. Jia Y., Jiang H., Valkeapää M., et al. Geometrical analysis of superstructures in YBaCo4O8.5 by electron diffraction / Sol. St. Ionics. 2011. Vol. 204 - 205. P. 7 - 12.

11. Waerenborgh J. C, Tsipis E. V., Pereira L. C. J., et al. Magnetization, Mössbauer and isothermal dilatometric behavior of oxidized YBa(Co, Fe)4O7 + δ / Dalton Trans. 2012. Vol. 41. P. 667 - 678.

12. Manuel P., Chapon L. C., Radaelli P. G., et al. Magnetic Correlations in the Extended Kagome YBaCo4O7 Probed by Single Crystal Neutron Scattering / Phys. Rev. Lett. 2009. Vol. 103. P. 037202-1 - 037202-4.

13. Подберезская Н. В., Козеева Л. П., Каменева М. Ю. и др. Уточнение состава и структуры кристаллов YBaCo4 - xAlxO7 + δ / Кристаллография. 2011. Т. 56. № 3. С. 459 - 469.

14. Подберезская Н. В., Смоленцев А. И., Козеева Л. П. и др. Иттрий-барий гептаоксокобальтат YBaCo4O7 + δ: уточнение структуры и состава / Кристаллография. 2013. Т. 58. № 4. С. 598 - 602.

15. Bruker AXS Inc. (2004) APEX2 (Version 1.08), SAINT (Version 7.03), SADABS (Version 2.11) and SHELXTL (Version 6.14) Bruker Advanced X_ray solution, Madison, USA, 1984. P. 64.

16. Sheldrick G. M. SHELX97 Release 97_2. University of Göttingen, Germany, 1998.