Increased bound magnetic polaron formation in the dilute magnetic semiconductor Zn1-xNixO

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Vol. 260; p. 114644
• Main Authors: Robkhob, Prissana, Tang, I-Ming, Thongmee, Sirikanjana
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-10-2020; Elsevier BV
• Subjects: Antiferromagnetism; Blue shift; Bound magnetic polarons; Dilute magnetic semiconductor; Doping; Electrons; Magnetic saturation; Magnetic semiconductors; Nanoparticles; Narrowing of the energy gap; Ni- doped ZnO nanoparticles; Tauc plots; Vacancies; Williamson-Hall plot; Wurtzite; Zinc oxide; Bound magnetic polarons; Williamson-Hall plot; Narrowing of the energy gap; Tauc plots; Ni- doped ZnO nanoparticles; Dilute magnetic semiconductor
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2020.114644

•The strain could be produced by doping ZnO NP’s with impurities having a size different from that of Zn.•PL spectra exhibit an increased blue shift as more Ni is doped in.•Peak at 388.41 nm is due to the recombination of electron and hole after their formation as an exciton.•The intensity of green emission peaks at 513–519 nm trend to increase as the amount of Ni increases.•Ms expressed as Bohr magneton/Ni ion decrease as more Ni2+ replace a non-magnetic Zn2+ ions.
Ni doped ZnO nanoparticles (NP’s) was fabricated by hydrothermal method. XRD result investigated that all peaks could be indexed to hexagonal wurtzite structure of ZnO NP’s with no impurity phases. The values of saturation magnetization when expressed in terms of emu/g increases as the doping level increases but decreases when MS is expressed in terms of µB/Ni ion. PL spectra exhibit an increased blue shift as more Ni doping. The blue shifts of the peak in the visible light spectrum of the PL emissions of the Ni doped ZnO NP’s also indicate that more singly ionized oxygen vacancies are being created. The combination of their being more polarized d electrons available and more singly ionized oxygen vacancies around which the d electrons of the Ni2+ ions can localize to form the BMP’s would lead to an increase in the antiferromagnetic contribution to the net exchange interaction between Ni ions to increase.