TY - JOUR
T1 - Control of inhomogeneity and magnetic properties of ZnO:Co films grown by magnetron sputtering using nitrogen
AU - Agusutrisno, M. N.
AU - Narishige, Ryota
AU - Kamataki, Kunihiro
AU - Okumura, Takamasa
AU - Itagaki, Naho
AU - Koga, Kazunori
AU - Shiratani, Masaharu
AU - Yamashita, Naoto
N1 - Funding Information:
This work was supported by JICA , JSPS KAKENHI Grant Numbers JP21H01372 , JP21K18731 , JP22H05000 , JP20H00142 , JP22K14292 , Core-to-Core program Grant Number JSPSCCA2019002 , Early-career Scientists Grant Number 22K14292 , Murata Science Foundation , and Iketani Science and Technology Foundation .
Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2023/8/1
Y1 - 2023/8/1
N2 - We experimentally report the control of structural inhomogeneity and magnetic properties of Co-doped ZnO films using nitrogen mediated-crystallization. The ZnO:CoN were grown on a silicon substrate at room temperature by RF-magnetron sputtering using nitrogen and followed by a post-annealing treatment for 3 hours at 400 °C, 600 °C, 800 °C and 1000 °C in the air. This method induces changes in inhomogeneity properties comprised by microstructure and stoichiometry of each film, which are confirmed by X-ray diffraction, thermal desorption, and X-ray fluorescence measurements. The difference in inhomogeneity has led to the transformation in the magnetic properties. Films annealed at 400 °C, which showed the highest inhomogeneity, exhibited superparamagnetic-ferromagnetic properties. In contrast, all the other films exhibited diamagnetic properties. Increasing the post-annealing temperature above 400 °C reduces inhomogeneities indicated by improved grain size, decreased impurities, and lattice parameters and stoichiometry of ZnO:CoN films approached those of pure ZnO. Our present results will contribute to control the inhomogeneity of ZnO:Co films to improve magnetic properties at room temperature.
AB - We experimentally report the control of structural inhomogeneity and magnetic properties of Co-doped ZnO films using nitrogen mediated-crystallization. The ZnO:CoN were grown on a silicon substrate at room temperature by RF-magnetron sputtering using nitrogen and followed by a post-annealing treatment for 3 hours at 400 °C, 600 °C, 800 °C and 1000 °C in the air. This method induces changes in inhomogeneity properties comprised by microstructure and stoichiometry of each film, which are confirmed by X-ray diffraction, thermal desorption, and X-ray fluorescence measurements. The difference in inhomogeneity has led to the transformation in the magnetic properties. Films annealed at 400 °C, which showed the highest inhomogeneity, exhibited superparamagnetic-ferromagnetic properties. In contrast, all the other films exhibited diamagnetic properties. Increasing the post-annealing temperature above 400 °C reduces inhomogeneities indicated by improved grain size, decreased impurities, and lattice parameters and stoichiometry of ZnO:CoN films approached those of pure ZnO. Our present results will contribute to control the inhomogeneity of ZnO:Co films to improve magnetic properties at room temperature.
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U2 - 10.1016/j.mssp.2023.107503
DO - 10.1016/j.mssp.2023.107503
M3 - Article
AN - SCOPUS:85152241743
SN - 1369-8001
VL - 162
JO - Materials Science in Semiconductor Processing
JF - Materials Science in Semiconductor Processing
M1 - 107503
ER -