THz ESR study of Spinel Compound GeCo2O4
-
Susumu Okubo
,
Tatsuya Ijima
Abstract
We performed terahertz ESR measurements of spin frustrated spinel compound GeCo2O4 using pulsed magnetic fields of up to 40 T. A very broad EPR absorption line was observed at 86 K. The g-values at 86 K were estimated to be g=5.26±0.07, 5.16±0.12 and 4.98±0.07 for B//[111], [100] and [110], respectively. High-field ESR measurements revealed complicated phase structures and a field-induced magnetic phase below 3 K. Critical fields of magnetic phases at 1.8 K for B//[111] were observed at 1.8 T, 5.0 T, 8.6 T, 11.0 T and 12.9 T for B//[111]. An energy gap of 300 GHz (=14.4 K=1.24 meV), which was related to the lattice deformation, was observed for B//[111]. The zero field gap of ω4 mode, which is considered to be a singlet-triplet excitation of the di-tetramer, was estimated to be 1120 GHz.
Dedicated to: Kev Salikhov on the occasion of his 80th birthday.
Acknowledgements
The authors would like to thank Prof. Kev Salikhov for fruitful discussions. This research was partially supported by a Grant-in-Aid for Challenging Exploratory Research (No. 26610104) and a Grant-in-Aid for Scientific Research (C) (No. 26400335) from the Japan Society for the Promotion of Science (JSPS).
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©2017 Walter de Gruyter GmbH, Berlin/Boston
Articles in the same Issue
- Frontmatter
- Preface
- Basic and Combination Cross-Features in X- and Q-band HYSCORE of the 15N Labeled Bacteriochlorophyll a Cation Radical
- An EPR Study of Small Magnetic Nanoparticles
- Magnetic Resonance Study of the Spin-1/2 Quantum Magnet BaAg2Cu[VO4]2
- Triarylmethyl Radicals: An EPR Study of 13C Hyperfine Coupling Constants
- Natural Abundance Nitrogen-15 NMR in Thermotropic Liquid Crystals With Cyano-Group
- Surface Hydroxyl OH Defects of η-Al2O3 and χ-Al2O3 by Solid State NMR, XRD, and DFT Calculations
- THz ESR study of Spinel Compound GeCo2O4
- Self-Association of Glycyrrhizic Acid. NMR Study
- A Site-Specific Study of the Magnetic Field-Dependent Proton Spin Relaxation of an Iridium N-Heterocyclic Carbene Complex
- Multifrequency Multiresonance EPR Investigation of Halogen-bonded Complexes Involving Neutral Nitroxide Radicals
- Electron Paramagnetic Resonance and DFT Analysis of the Effects of Bulky Perfluoroalkyl Substituents on a Vanadyl Perfluoro Phthalocyanine
- Coordination of the Mn4+-Center in Layered Li[Co0.98Mn0.02]O2 Cathode Materials for Lithium-Ion Batteries
- Triarylmethyl Radical: EPR Signal to Noise at Frequencies between 250 MHz and 1.5 GHz and Dependence of Relaxation on Radical and Salt Concentration and on Frequency
Articles in the same Issue
- Frontmatter
- Preface
- Basic and Combination Cross-Features in X- and Q-band HYSCORE of the 15N Labeled Bacteriochlorophyll a Cation Radical
- An EPR Study of Small Magnetic Nanoparticles
- Magnetic Resonance Study of the Spin-1/2 Quantum Magnet BaAg2Cu[VO4]2
- Triarylmethyl Radicals: An EPR Study of 13C Hyperfine Coupling Constants
- Natural Abundance Nitrogen-15 NMR in Thermotropic Liquid Crystals With Cyano-Group
- Surface Hydroxyl OH Defects of η-Al2O3 and χ-Al2O3 by Solid State NMR, XRD, and DFT Calculations
- THz ESR study of Spinel Compound GeCo2O4
- Self-Association of Glycyrrhizic Acid. NMR Study
- A Site-Specific Study of the Magnetic Field-Dependent Proton Spin Relaxation of an Iridium N-Heterocyclic Carbene Complex
- Multifrequency Multiresonance EPR Investigation of Halogen-bonded Complexes Involving Neutral Nitroxide Radicals
- Electron Paramagnetic Resonance and DFT Analysis of the Effects of Bulky Perfluoroalkyl Substituents on a Vanadyl Perfluoro Phthalocyanine
- Coordination of the Mn4+-Center in Layered Li[Co0.98Mn0.02]O2 Cathode Materials for Lithium-Ion Batteries
- Triarylmethyl Radical: EPR Signal to Noise at Frequencies between 250 MHz and 1.5 GHz and Dependence of Relaxation on Radical and Salt Concentration and on Frequency
