Electrical and thermal conductivities of rare-earth A2Zr2O7 (A = Pr, Nd, Sm, Gd, and Er)



Título del documento: Electrical and thermal conductivities of rare-earth A2Zr2O7 (A = Pr, Nd, Sm, Gd, and Er)
Revue: Revista mexicana de física
Base de datos: PERIÓDICA
Número de sistema: 000447095
ISSN: 0035-001X
Autores: 1
2
3
4
5
6
Instituciones: 1Universidad Tecnológica de Xicotepec de Juárez, Area deMantenimiento Industrial y Petróleo, Xicotepec de Juárez, Puebla. México
2Benemérita Universidad Autónoma de Puebla, Instituto de Física "Luis Rivera Terrazas", Puebla. México
3Instituto Politécnico Nacional, Altamira, Tamaulipas. México
4Benemérita Universidad Autónoma de Puebla, Facultad de Ciencias Físico-Matemáticas, Puebla. México
5Universidad Nacional Autónoma de México, Instituto de Investigaciones en Materiales, Ciudad de México. México
6Universidad Autónoma del Carmen, Facultad de Ingeniería, Ciudad del Carmen, Campeche. México
Año:
Periodo: Mar-Abr
Volumen: 67
Número: 2
Paginación: 255-262
País: México
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Analítico, teórico
Resumen en inglés Structural and thermoelectric properties of rare-earth zirconates A2Zr2O7, with A = Pr, Nd, Sm, Gd, and Er, were studied. Samples were prepared by solid-state reaction at ambient pressure with temperatures between 1000 and 1400 ◦C. The resulting compounds were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM/EDS). The XRD analyses showed the formation of polycrystalline Pr2Zr2O7, Nd2Zr2O7, Sm2Zr2O7, Gd2Zr2O7, and Er2Zr2O7 phases, with a cubic cell (space group Fm3m) and traces of the raw used materials. The micrographs obtained by SEM show the formation of heterogeneous grains with a size that ranges from 0.7 to 4.7 µm. All A2Zr2O7 samples present porous surfaces. Thermal conductivities were measured at different temperatures, from 300 to 900 K. In most of the samples, the thermal conductivity monotonically decreases with temperature, from 0.40 - 1.17 W/mK at 300 K to 0.27 - 0.77 W/mK at 773.15 K. At a fixed temperature, the thermal conductivity decreases almost monotonically with the ionic radius (IR) of the rare-earth elements (where IR (Er3+) = 0.890 Å < IR (Gd3+) = 0.938 Å < IR (Sm3+) = 0.958 Å < IR (Nd3+) = 0.983 Å < IR (Pr3+) = 0.99 Å)
Disciplinas: Ingeniería
Palabras clave: Ingeniería petrolera,
Ingeniería de materiales,
Química del estado sólido,
Análisis térmico,
Difracción de rayos X,
Dispersión de rayos X,
Termoeléctricas,
Zirconia
Keyword: Petroleum engineering,
Materials engineering,
Solid state chemistry,
Thermal analysis,
X-ray diffraction,
X-ray scattering,
Thermoelectrics,
Zircon
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