Experimental and theoretical investigations on low temperature EPR of Cu2+ centers in TiO2 rutile single crystal

• Published in: Journal of alloys and compounds 2017-07, Vol.710, p.836-842
• Main Authors: Zerentürk, A., Açıkgöz, M., Kazan, S., Yıldız, F., Khaibullin, R.I., Rameev, B., Aktaş, B.
• Format: Article
• Language: English
• Subjects: Copper; Crystallography; Cu2; Electron spin; EPR; Experiments; Ion implantation; Low temperature; Misalignment; Nuclear spin; Planes; Rutile; Semiconductors; Single crystals; Temperature; TiO2; Titanium dioxide; Titanium oxides
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.03.330

We present the results of low-temperature (7–13 K) EPR investigation on Cu2+ doped rutile TiO2 with ion implantation. Spin Hamiltonian containing electronic Zeeman and hyperfine terms was used to analyze experimental data since Cu2+ ions have ½ effective spin and their nuclear spin 3/2. The spectra show that there are two equivalent paramagnetic Cu2+ centers and they substitute for Ti4+ ion sites in the TiO2 rutile lattice. Exact diagonalization of spin Hamiltonian is used to analyze EPR spectra, and the small misalignment of sample from the exact crystallographic planes is taken into account. The g tensor values are found as gx = 2.1143, gy = 2.0907, gz = 2.3394 and principal values of hyperfine tensor for 63Cu2+ are Ax = 30.6, Ay = 34.7, Az = −93.2 and for 65Cu2+ Ax = 33.5, Ay = 36.7, Az = −99.0 (in 10−4/cm). •X-band EPR spectra of Cu2+ ion doped rutile (TiO2) investigated at 7–13 K.•The presence of two structurally equivalent centers for Cu2+ ions observed.•Theoretical analysis using exact diagonalization (ED) analysis carried out.•It is concluded that impurity ions substitute for Ti4+ ion.