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Title: High-field/high-frequency electron spin resonances of Fe-doped β Ga 2 O 3 by terahertz generalized ellipsometry: Monoclinic symmetry effects

Journal Article · · Physical Review. B
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We demonstrate detection and measurement of electron paramagnetic spin resonances (EPR) of iron defects in β Ga 2 O 3 utilizing generalized ellipsometry at frequencies between 110 and 170 GHz. The experiments are performed on an Fe-doped single crystal in a free-beam configuration in reflection at 45 and magnetic fields between 3 and 7 T. In contrast with low-field, low-frequency EPR measurements, we observe all five transitions of the s = 5 / 2 high-spin state Fe 3 + simultaneously. We confirm that ferric Fe 3 + is predominantly found at octahedrally coordinated Ga sites. We obtain the full set of fourth-order monoclinic zero-field splitting parameters for both octahedrally and tetrahedrally coordinated sites by employing measurements at multiple sample azimuth rotations. The capability of high-field EPR allows us to demonstrate that simplified second-order orthorhombic spin Hamiltonians are insufficient, and fourth-order terms as well as consideration of the monoclinic symmetry are needed. These findings are supported by computational approaches based on density-functional theory for second-order and on ligand-field theory for fourth-order parameters of the spin Hamiltonian. Terahertz ellipsometry is a way to measure spin resonances in a cavity-free setup. Its possibility of varying the probe frequency arbitrarily without otherwise changing the experimental setup offers unique means of truly disentangling different components of highly anisotropic spin Hamiltonians. Published by the American Physical Society 2024

Sponsoring Organization:
USDOE
Grant/Contract Number:
SC0012704
OSTI ID:
2372800
Journal Information:
Physical Review. B, Journal Name: Physical Review. B Journal Issue: 21 Vol. 109; ISSN 2469-9950; ISSN PRBMDO
Publisher:
American Physical SocietyCopyright Statement
Country of Publication:
United States
Language:
English

References (73)

Erratum: “Hybrid functionals based on a screened Coulomb potential” [J. Chem. Phys. 118, 8207 (2003)] journal June 2006
Electronic properties of the residual donor in unintentionally doped β-Ga2O3 journal December 2016
Deep donor behavior of iron in β-Ga 2 O 3 crystals: Establishing the Fe 4+/3+ level journal October 2020
Electron paramagnetic resonance and theoretical study of gallium vacancy in β -Ga 2 O 3 journal July 2020
Electrostatic interactions between charged defects in supercells journal December 2010
β-Gallium oxide power electronics journal February 2022
Integer-spin electron paramagnetic resonance of iron proteins journal September 1989
On standardization and algebraic symmetry of the ligand field Hamiltonian for rare earth ions at monoclinic symmetry sites journal May 1986
Importance of Fourth-Order Zero-Field Splitting Terms in Random-Orientation EPR Spectra of Eu(II)-Doped Strontium Aluminate journal November 2003
Electron paramagnetic resonance signatures of Co2+ and Cu2+ in β-Ga2O3 journal December 2019
Singular optical axes in biaxial crystals and analysis of their spectral dispersion effects inβ−Ga2O3 journal May 2016
Projector augmented-wave method journal December 1994
First principles calculation of spin-related quantities for point defect qubit research journal December 2018
Ab initio molecular dynamics for open-shell transition metals journal November 1993
Wide Bandgap Oxide Semiconductors: from Materials Physics to Optoelectronic Devices journal April 2021
Non-Kramers iron S = 2 ions in β-Ga2O3 crystals: High-frequency low-temperature EPR study journal October 2022
Magnetic properties and energy-mapping analysis journal January 2013
Longitudinal phonon plasmon mode coupling in β -Ga 2 O 3 journal March 2019
EasySpin, a comprehensive software package for spectral simulation and analysis in EPR journal January 2006
Terahertz electron paramagnetic resonance generalized spectroscopic ellipsometry: The magnetic response of the nitrogen defect in 4H-SiC journal March 2022
Proton irradiation induced defects in β-Ga 2 O 3 : A combined EPR and theory study journal February 2019
Zero-field splitting in metal complexes journal May 2004
Electrical properties of bulk semi-insulating β-Ga 2 O 3 (Fe) journal October 2018
Dielectric and conducting properties of unintentionally and Sn-doped β-Ga2O3 studied by terahertz spectroscopy journal April 2020
Correlation between blue luminescence intensity and resistivity in β -Ga 2 O 3 single crystals journal July 2013
Lateral β -Ga 2 O 3 field effect transistors journal November 2019
Slow spin relaxation in single endohedral fullerene molecules journal December 2021
PyCrystalField : software for calculation, analysis and fitting of crystal electric field Hamiltonians journal February 2021
Hybrid functionals based on a screened Coulomb potential journal May 2003
Fully Ab Initio Finite-Size Corrections for Charged-Defect Supercell Calculations journal January 2009
A 220 GHz–1.1 THz continuous frequency and polarization tunable quasi-optical electron paramagnetic resonance spectroscopic system journal March 2023
A review of Ga 2 O 3 materials, processing, and devices journal March 2018
High-quality β-Ga 2 O 3 single crystals grown by edge-defined film-fed growth journal November 2016
Ultra-broadband EPR spectroscopy in field and frequency domains journal January 2018
Advanced Terahertz Frequency-Domain Ellipsometry Instrumentation for In Situ and Ex Situ Applications journal May 2018
Band-to-band transitions, selection rules, effective mass, and excitonic contributions in monoclinic β − Ga 2 O 3 journal December 2017
VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data journal October 2011
Iron and intrinsic deep level states in Ga 2 O 3 journal January 2018
Anisotropic complex refractive index of β-Ga2O3 bulk and epilayer evaluated by terahertz time-domain spectroscopy journal January 2021
Experimental determination of the (0/−) level for Mg acceptors in β -Ga 2 O 3 crystals journal April 2020
Electrical Properties, Deep Levels and Luminescence Related to Fe in Bulk Semi-Insulating β-Ga 2 O 3 Doped with Fe journal January 2019
Optical transitions for impurities in Ga 2 O 3 as determined by photo-induced electron paramagnetic resonance spectroscopy journal February 2020
Deep donors and acceptors in β-Ga 2 O 3 crystals: Determination of the Fe 2+/3+ level by a noncontact method journal December 2019
Growth of β-Ga 2 O 3 Single Crystals by the Edge-Defined, Film Fed Growth Method journal November 2008
Electron-spin resonance of transparent conductive oxide β-Ga2O3 journal September 2012
Ir 4+ ions in β-Ga 2 O 3 crystals: An unintentional deep donor journal January 2019
Dipole analysis of the dielectric function of color dispersive materials: Application to monoclinic Ga 2 O 3 journal July 2016
Charge trapping at Fe due to midgap levels in Ga2O3 journal February 2021
Perspective: Ga 2 O 3 for ultra-high power rectifiers and MOSFETS journal December 2018
Electron paramagnetic resonance study of neutral Mg acceptors in β-Ga 2 O 3 crystals journal August 2017
Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set journal October 1996
Electron paramagnetic resonance characterization of Cr3+ impurities in a β-Ga2O3 single crystal journal March 2003
Restoring the Density-Gradient Expansion for Exchange in Solids and Surfaces journal April 2008
Electrical properties of β -Ga 2 O 3 single crystals grown by the Czochralski method journal September 2011
First principles method for the calculation of zero-field splitting tensors in periodic systems journal January 2008
β -Ga 2 O 3 for wide-bandgap electronics and optoelectronics journal October 2018
Influence of strain and chemical substitution on the magnetic anisotropy of antiferromagnetic Cr 2 O 3 : An ab-initio study journal March 2019
On standardization of the spin Hamiltonian and the ligand field Hamiltonian for orthorhombic symmetry journal November 1985
The anisotropic quasi-static permittivity of single-crystal β-Ga2O3 measured by terahertz spectroscopy journal December 2020
Point-Charge Calculations of Energy Levels of Magnetic Ions in Crystalline Electric Fields book January 1964
A New Q-Band EPR Probe for Quantitative Studies of Even Electron Metalloproteins journal February 1999
Optical absorption of Fe in doped Ga 2 O 3 journal October 2019
On the bulk β-Ga2O3 single crystals grown by the Czochralski method journal October 2014
Identification of different iron sites in β-Ga2O3 nanoparticles by spectroscopic methods conference January 2015
β‐Gallium Oxide Devices: Progress and Outlook journal October 2021
Correlation of Zero-Field Splittings and Site Distortions. IX. Fe3+ and Cr3+ in β -Ga2O3 journal January 1987
Anisotropy, phonon modes, and free charge carrier parameters in monoclinic β -gallium oxide single crystals journal March 2016
Determination of the correlation between the crystal field axis system and the crystallographic axes in chromium‐doped β‐Ga2O3 by EPR journal March 1983
Structural and electronic characteristics of Fe-doped β-Ga2O3 single crystals and the annealing effects journal May 2021
Dielectric tensor of monoclinic Ga 2 O 3 single crystals in the spectral range 0.5–8.5 eV journal October 2015
Theoretical unification of hybrid-DFT and DFT   +   U methods for the treatment of localized orbitals journal July 2014
Role of screening in the density functional applied to transition-metal defects in semiconductors journal May 2013
Spectroscopic Ellipsometry book January 2007