M A Hosain¹ , J-M Le Floch^1,2, J Krupka³ and M E Tobar¹
1 ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, University of Western
Australia, 35 Stirling Highway, Crawley WA 6009, Australia
2 MOE Key Laboratory of Fundamental Physical Quantities Measurement, School of Physics, Huazhong
University of Science and Technology, Wuhan 430074, Hubei, People’s Republic of China
3 Department of Electronics and Information Technology, Institute of Microelectronics
and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warszawa, Poland

The impurity paramagnetic ion, Cu²⁺ substitutes Al in the SrLaAlO₄ single crystal lattice, this results in a CuO₆ elongated octahedron, and the resulting measured g-factors satisfy four-fold axes variation condition. The aggregate frequency width of the electron spin
resonance with the required minimum level of impurity concentration has been evaluated in this single crystal SrLaAlO₄ at 20 millikelvin. Measured parallel hyperfine constants, A Cu, were determined to be −155.7 × 10⁻⁴ cm⁻¹, − 163.0 × 10⁻⁴ cm⁻¹, − 178.3 × 10⁻⁴ cm⁻¹ and −211.1 × 10⁻⁴ cm⁻¹ at 9.072 GHz (WGH_4,1,1) for the nuclear magnetic quantum number MI = +3/2,+1/2,−1/2, and−3/2 respectively. The anisotropy of the hyperfine structure reveals the characteristics of the static Jahn–Teller effect. The second-order-anisotropy term, ~( spin−orbit coupling/10D_q)², is significant and cannot be disregarded, with the local strain dominating over the observed Zeeman-anisotropy-energy difference. The Bohr electron magneton, = 9.23 × 10⁻²⁴JT⁻¹, (within −0.43% so-called experimental error) has been found using the measured spin-Hamiltonian parameters. Measured nuclear dipolar hyperfine structure parameter P = 12.3 × 10⁻⁴ cm⁻¹ shows that the mean inverse third power of the electron distance from the nucleus is r_q⁻³ ~= 5.23 a.u. for Cu²⁺ ion in the substituted Al³⁺ ion site assuming nuclear electric quadruple moment Q = −0.211 barn.

https://doi.org/10.1088/1361-648X/aa9a1e