High Field/High Frequency ESR in Osaka University

Kimura, Shojiro; Kindo, Koichi; Narumi, Yasuo; Hagiwara, Masayuki; Kikuchi, Hikomitsii; Ajiro, Yoshitami

doi:10.1143/jpsjs.72sb.99

Cited by 14 publications

(6 citation statements)

References 42 publications

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“…The energy of the excitation is quite close to the anisotropy energy of the natural oxygen in the gas phase reported as 0.5 meV. [27] This suggested that the excitation is due to the single-ion-anisotropy of the adsorbed oxygen molecules.…”

Section: Resultssupporting

confidence: 66%

Spin Model of O₂-Based Magnet in a Nanoporous Metal Complex

et al. 2016

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Inelastic neutron scattering experiments are performed on a nanoporous metal complex Cu-Trans-1,4-Cyclohexanedicarboxylic Acid (Cu-CHD) adsorbing O2 molecules to identify the spin model of the O2-based magnet realized in the host complex. It is found that the magnetic excitations of Cu-CHDs adsorbing low-and high-concentration O2 molecules are explained by different spin models, the former by spin dimers and the latter by spin trimers. By using the obtained parameters and also by assuming that the levels of the higher energy states are reduced because of the non-negligible spin dependence of the molecular potential of oxygen, the magnetization curves are explained in quantitative level.

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Section: Resultssupporting

confidence: 66%

Spin Model of O₂-Based Magnet in a Nanoporous Metal Complex

et al. 2016

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“…Thus, the adsorbed O 2 molecules will form soft aggregates in the channel. Although the changes of magnetization indicated changes in the magnetic interaction of the O 2 aggregates that were induced by magnetic anisotropy, the energy difference in the change of the configuration of the included O 2 aggregates is too low to be observed under the condition in which the applied magnetic field is low and the temperature of the measurement is high compared with the magnetic anisotropic energy of the O 2 molecules ( D = 5.8 K for the gas phase) . These results suggest that the flexible host stabilizes the configuration of the O 2 aggregates, which enable observation of the states of slightly different energy levels.…”

Section: Resultsmentioning

confidence: 90%

Structural and Magnetic Study of O₂ Molecules Arranged along a Channel in a Flexible Single-Crystal Host Family

et al. 2008

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We report the magnetic behaviors of O(2) molecules, which aligned in the channels of four types of single-crystal adsorbents, [M(2)(bza)(4)(pyz)](n) (bza = benzoate; pyz = pyrazine; M = Rh(II) (1a) and Cu(II) (1b)) and [M(2)(bza)(4)(2-mpyz)](n) (2-mpyz = 2-methylpyrazine; M = Rh(II) (2a) and Cu(II) (2b)). The X-ray single-crystal structures at various temperatures from 10 to 298 K were determined for O(2)-included crystals of 1a and 2a. All adsorbed O(2) molecules exhibited abnormal magnetic phases above 4 T in the temperature range around 55-105 K. The magnetic behaviors of adsorbed O(2) molecules between four inclusions were discussed. The existence of the metastable state, which was also suggested by hysteresis on the M-H curves, was revealed by analysis of the time course of the magnetization. Considering that the abnormal magnetic behavior occurred at relatively high temperatures and a low magnetic field, it was suggested that these behaviors were induced because of the changes of magnetic interaction of included O(2) aggregates involving transformation which is supported by the surrounding of the channels of the single-crystal hosts under the applied magnetic field.

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“…The high field ESR measurements are performed using this pulsed magnetic field and FIR laser. 29) Okayama University is a new facility which started in April, 2001. 30) They prepared the 3 He system to perform submillimeter wave ESR down to 0.5 K. They are preparing the submillimeter wave ESR system equipped with the repeated pulsed magnetic field which is a new technique promising for gaining the signal-tonoise ratio in high field ESR measurements.…”

Section: )mentioning

confidence: 99%

“…29 magnetic field, and temperature dependence of the line width in Cu-benzoate, 40) whcih was known but unsolved for a long time. The field and temperature dependences of the line width were clearly interpreted by the (H /T ) 2 behavior obtained by the OA theory.…”

Section: )mentioning

confidence: 99%

Submillimeter Wave ESR System Using the Pulsed Magnetic Field and Its Applications to One Dimensional Antiferromagnetic System

et al. 2003

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Submillimeter wave ESR measurements using the pulsed magnetic field is a powerful spectroscopic technique covering the wide frequency and magnetic field range with many advantages compared to the conventional X-band ESR measurements. Recent submillimeter wave ESR results showed that it is especially powerful to study the low dimensional antiferromagnets, are also presented. As an example of the study of quantum spin system, the investigation of the S=1/2 one dimensional antiferromagnets BaCu 2 (Si 1−x Ge x ) 2 O 7 (x=0, x=0.65), which have the staggered field effect in the system, is also presented in connection with the recent ESR theory by Oshikawa and Affleck (OA). Although both x=0 and x=0.65 systems show one dimensional behavior from the magnetic susceptibility, the temperature and frequency dependences of the mixed crystal x=0.65 system are well interpreted by the OA theory while they are not for the pure x=0 system. The antiferromagnetic resonance measurements of x=0 system (T N =8.9 K) have been performed up to 30 T at 1.8 K, and the magnetic phase transitions at 7 T and 16 T for H//a and H//c, respectively, are suggested for the first time.KEYWORDS: high field, high frequency, ESR, quantum spin system, line width, AFMR, BaCu 2 (Si 1−x Ge x ) 2 O 7 Submillimeter wave ESR and its facilities in JapanSubmillimeter wave ESR or, in other words, high field ESR measurements use higher frequency and higher magnetic field compared to the conventional X-band ESR measurement, which uses about 9.5 GHz and water cooling steady field up to 1 T. Due to these higher frequency and higher magnetic field, the submillimeter wave ESR has several advantages compared to the conventional X-band ESR. 1-3)(1) Stronger ESR absorption intensity (2) Higher resolution (3) Observation of a broad absorption line (4) Observation of ESR across the large energy splitting (5) Observation of ESR mode above the magnetic phase transition (6) Estimation of interchain exchange interaction in quasi one dimensional (1D) antiferromagnet The absorption intensity of ESR is proportional to the difference of Boltzman distribution between S Z =-1/2 and S Z =1/2 states, which are split by the Zeeman effect. Therefore, in principle, one will get stronger absorption intensity as one goes to the higher frequency because the Zeeman splitting will be larger. However, in reality, X-band ESR uses lock-in detection, a cavity etc. and has relatively higher sensitivity than submillimeter wave ESR. This means, on the contrary, there is still enough room for the submillimter wave ESR to gain its sensitivity, and we have to work on that. The magnetic field difference between the resonances with different gvalues becomes larger as the frequency is increased. If * E-mail address: ohta@phys.sci.kobe-u.ac.jp the field difference becomes larger than the line width, it will be easier to distinguish two resonances. Therefore, the submillimeter wave ESR gives higher resolution and this merit is also useful when analyzing the powder absorption.4) The line width of ESR is rel...

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High Field/High Frequency ESR in Osaka University

Cited by 14 publications

References 42 publications

Spin Model of O₂-Based Magnet in a Nanoporous Metal Complex

Spin Model of O₂-Based Magnet in a Nanoporous Metal Complex

Structural and Magnetic Study of O₂ Molecules Arranged along a Channel in a Flexible Single-Crystal Host Family

Submillimeter Wave ESR System Using the Pulsed Magnetic Field and Its Applications to One Dimensional Antiferromagnetic System

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High Field/High Frequency ESR in Osaka University

Cited by 14 publications

References 42 publications

Spin Model of O2-Based Magnet in a Nanoporous Metal Complex

Spin Model of O2-Based Magnet in a Nanoporous Metal Complex

Structural and Magnetic Study of O2 Molecules Arranged along a Channel in a Flexible Single-Crystal Host Family

Submillimeter Wave ESR System Using the Pulsed Magnetic Field and Its Applications to One Dimensional Antiferromagnetic System

Contact Info

Product

Resources

About

Spin Model of O₂-Based Magnet in a Nanoporous Metal Complex

Spin Model of O₂-Based Magnet in a Nanoporous Metal Complex

Structural and Magnetic Study of O₂ Molecules Arranged along a Channel in a Flexible Single-Crystal Host Family