Cobalt doping effects on photoluminescence, Raman scattering, crystal structure, and magnetic and piezoelectric properties in ZnO single crystals grown from molten hydrous LiOH and NaOH solutions

• Published in: Journal of alloys and compounds Vol. 628; pp. 303 - 307
• Main Authors: Zhao, Lan-Ling, Wang, Ji-Yang, Wang, Xiao-Lin, Cheng, Zhen-Xiang, Wang, Jun, Yin, Na, Gai, Zhi-Gang, Jalalian, Abolfazl, Dou, Shi-Xue
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.04.2015
• Subjects: Crystal growth; Dielectric response; Luminescence; Magnetic measurements; Semiconductors; ZnO; Crystal growth; Dielectric response; Magnetic measurements; ZnO; Semiconductors; Luminescence
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2014.12.148

•Zn1-xCoxO single crystals are successfully grown from molten hydrous LiOH and NaOH solutions.•The lattice parameters and bond lengths decrease with increasing cobalt concentration.•Cobalt doping leads to two new PL peaks and the disappearance of certain Raman active modes.•The Zn1−xCoxO crystals are typically paramagnetic.•The Zn1−xCoxO crystals have the same piezoelectricity as the un-doped ZnO. Transparent, olive-green single-crystal Zn1−xCoxO in the form of hexagonal lamellae grown from molten hydrous LiOH and NaOH solutions have been studied in terms of crystal structure, optical properties, Raman scattering, and magnetic and piezoelectric properties. Rietveld refinement shows that the lattice parameters and bond lengths decrease with increasing cobalt concentration. Cobalt doping results in slight changes to the piezoelectricity of ZnO, but leads to two new photoluminescence emission peaks at wavelengths of 443 and ∼510nm, along with the disappearance of certain Raman active modes. Furthermore, the ferromagnetic state is absent in all Zn1−xCoxO crystals, and they are all typically paramagnetic instead.