Structural properties of nanometre-sized ZnO crystals doped with Co

Abstract

Nanometre-sized ZnO crystals doped with Co were synthesized by a co-precipitation method combined with a thermal treatment. By changing the reaction temperature, we can control the crystallite size from roughly 10 nm particles to 20 nm × 200 nm nm rods grown along the hexagonal c-direction. X-ray diffraction and Raman scattering showed growth of high-quality wurtzite ZnO crystals incorporating Co systematically in the ZnO host lattice in the tested range of [Co]<3.0 mol%. Electronic transitions of Co in the oxygen tetrahedron were also observed in optical absorption, giving supporting evidence for systematic substitution of Co into the Zn site.

Room temperature ferromagnetism in Mn-doped zinc oxide nanorods prepared by hybrid wet chemical route

“…Thus, we apprehend that this Raman peak at ∼660 cm −1 did not originate from possible partial formation of Mnrich solid solution layer in the Mn:ZnO nanorods or precipitation of ZnMn 2 O 4 . Rather, this peak might have originated from the combined effect of two-phonon signal of ZnO as indicated by Calleja and Cardona [32] and Hasuike et al [33] and the vibration mode of Mn-O as observed by Xu et al [29].…”

Structural and electronic properties of Co‐doped ZnO nanocrystals synthesized by co‐precipitation method

“…In previous report [13], ZnO nanocrystals doped with Co with the dimension of 10 nm were successfully synthesized by co-precipitation method, and Co ions were systematically substituted in Zn sites.…”

“…method with post-thermal treatment at 70 °C [13]. All the samples had wurtzite structure of ~10 nm, regardless the Co doping level, and secondary products such as precipitates of Co or its oxide were not present.…”

Synthesis and caractherization of a ZnO doped with Au semiconductor for gas sensors

“…La figura 9 muestra del espectro de absorbancia de las películas de Zn1-xAuxO, en la cual se observa una gran absorción por parte del ZnO a las temperaturas de recocido de 400 °C, 500 °C y 600 °C; coincidiendo con el trabajo realizado por Hasuike et al (2007). Se observa un pequeño aumento en la absorción óptica a medida que incrementa la temperatura de recocido; esto se debe a que en el ZnO a mayores temperaturas hay una disminución de defectos puntuales del tipo Schottky, o defectos catiónicos (metal-deficiente), quienes a la vez generan una disminución de la brecha energética, como referencian los autores Al-Ghamdi et al (2013) y Dilonardo et al (2016.…”