INVESTIGATION OF A NANOCRYSTALLINE YBA2CU3O7-DELTA POWDER BY NEUTRON AND ELECTRO

2020-04-05 17:14:53

temperature electron Of diffraction microscopy

责任者: WEYL, C;ZHAO, J;LACOUR, C;LAHERLACOUR, F;THUERY, P 单位: ESPCI,CERAM & MAT MINERAUX LAB,F-75231 PARIS,FRANCE.;CTR ETUD SACLAY,CEA,CNRS,LAB LEON BRILLOUIN,F-91191 GIF SUR YVETTE,FRANCE. 来源出处: JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, v 56, SEP 1995, p 1211- 1221 摘要: The structural characterization of a submicron-sized YBaCuO powder sample, obtained by freeze-drying preparation, was carried out using neutron diffraction from room temperature down to liquid helium temperature. A temperature independent broadening of the diffraction lines indicates a finite size of about 40 nm for the diffracting domains. No orthorhombic strain anomaly in the vicinity of the critical temperature T-c was detected. The unit cell volume reduction in the whole range 300-4.2 K, delta V congruent to 2.1 Angstrom(3), is larger than previously published values. High resolution electron diffraction confirms the existence of well-ordered crystalline domains with a size reaching ten nanometers. In addition, some electron diffraction patterns exhibit superlattice reflections, the origin of which will be discussed. 关键词: NANOSTRUCTURES; ELECTRON DIFFRACTION; ELECTRON MICROSCOPY; NEUTRON SCATTERING; SUPERCONDUCTIVITY SCATTERING; SUPERCONDUCTIVITY; X-RAY; SUPERCONDUCTING TRANSITION; SINGLE-CRYSTALS; TC; TEMPERATURE; MICROSCOPY; BA2YCU3O7; MAGNETORESISTANCE; MICROSTRUCTURE; PARTICLES MICROSCOPY; BA2YCU3O7; MAGNETORESISTANCE; MICROSTRUCTURE; PARTICLES