20 results on '"Takayoshi Yokoya"'
Search Results
2. Superconductivity in the α-Form Layer Structured Metal Nitride Halide
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Masashi Tanaka, Noriyuki Kataoka, and Takayoshi Yokoya
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α-form layered nitride halides ,intercalation ,electron doping ,superconducting mechanism ,photoemission spectroscopy ,Physics ,QC1-999 - Abstract
Layered metal nitride halides MNX (M = Ti, Zr, Hf; X = Cl, Br, I) have two polymorphs, including α- and β-forms, which have the FeOCl and SmSI structures, respectively. These compounds are band insulators and become metals and show superconductivity after electron doping by intercalating alkali metals between the layers. The superconductivity of β-form had been extensively characterized from decades ago, but it is not easy to consistently interpret all experimental results using conventional phonon-mediated Bardeen–Cooper–Schriefer mechanisms. The titanium compound TiNCl crystallizes only in the α-form structure. TiNCl also exhibits superconductivity as high as ~16 K after electron doping by intercalating metals and/or organic basis. It is important to compare the superconductivity of different M–N networks. However, α-form compounds are vulnerable to moisture, unlike β-form ones. The intercalation compounds are even more sensitive to humid air. Thus, there are few experimental studies on the superconducting mechanism of α-form, although it has been discussed for exotic Cooper-pairing mechanisms. This short review gathers the recent progress in experimental studies of TiNCl.
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- 2022
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3. μ-PES Studies on TiNCl and Quasi-two-dimensional Superconductor Na-intercalated TiNCl.
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Noriyuki Kataoka, Kensei Terashima, Masashi Tanaka, Wataru Hosoda, Takumi Taniguchi, Takanori Wakita, Yuji Muraoka, and Takayoshi Yokoya
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Electron-doped TiNCl is a superconductor, for which exotic mechanisms of the superconductivity have been discussed. However, difficulty in preparing large single-phase samples has prevented the direct observation of its electronic structure and how that changes with electron doping. In this study, micro-photoemission spectroscopy (μ-PES) was used to reveal the electronic structures of TiNCl and Na-intercalated TiNCl (Na-TiNCl). Comparison of Ti 2p core-level spectra shows the enhancement of a spectral feature in Na-TiNCl that suggests an increase in its metallic character. This indicates the introduction of electron carriers to the TiNCl layers. Although the overall valence band electronic structure of parent TiNCl could be reproduced by first-principle calculations, that of Na-TiNCl showed a marked deviation from the rigid band model near the Fermi level (E
F ). The spectral shape observed near EF of Na-TiNCl was found to be similar to a result in early transition metal oxides that has been attributed to the effect of strong electron correlation. The present study also demonstrated the usefulness of μ-PES to obtain reliable electronic structure data for samples that are difficult to make at large sizes. [ABSTRACT FROM AUTHOR]- Published
- 2019
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4. Cytokine modulation in abdominal septic shock via the crucial role of IL-6 signaling in endothelial dysfunction
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Takuya Ueno, Toshiaki Ikeda, Masaaki Okihara, Isao Akashi, Takayoshi Yokoyama, Yu Kihara, Osamu Konno, Yuki Nakamura, Hitoshi Iwamoto, Yu Ueno, and Anil Chandraker
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inflammatory cytokines ,Endothelial (dys)function ,abdominal septic shock ,Renal replacemant therapy ,PMX (polymyxin B-immobilized fiber column) ,Medicine (General) ,R5-920 - Abstract
BackgroundEarly recovery from shock improves prognosis in septic shock patients. We determined whether cytokine modulation by Continuous Renal Replacement Therapy (CRRT) following acute care surgery resulted in stable hemodynamics in them. To investigate our hypothesis, we measured proinflammatory cytokines IL-6, IL-1ra and the coagulation cascade activator plasminogen activator inhibitor-1 (PAI-1) following CRRT with polymyxin B immobilized fiber (PMX-DHP) which has been utilized as an adjuvant treatment option for patients with severe septic shock.Methods66 septic shock patients requiring 2 h direct hemoperfusion therapy PMX-DHP were included. 36 patients of them also received continuous hemodiafiltration (CHDF) after performing PMX-DHP. Circulatory dynamics and levels of inflammatory mediators, namely IL-6, IL-1ra, and PAI-1 were assessed before, immediately after, and 24 h initiation of PMX-DHP.ResultsMean Arterial Pressure (MAP) rose intentionally by PMX-DHP just after enforcement 24 h later (p
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- 2023
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5. Selective Reduction Mechanism of Graphene Oxide Driven by the Photon Mode versus the Thermal Mode.
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Masaki Hada, Kiyoshi Miyata, Satoshi Ohmura, Yusuke Arashida, Kohei Ichiyanagi, Ikufumi Katayama, Takayuki Suzuki, Wang Chen, Shota Mizote, Takayoshi Sawa, Takayoshi Yokoya, Toshio Seki, Jiro Matsuo, Tomoharu Tokunaga, Chihiro Itoh, Kenji Tsuruta, Ryo Fukaya, Shunsuke Nozawa, Shin-ichi Adachi, and Jun Takeda
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- 2019
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6. Observation of a Hidden Hole-Like Band Approaching the Fermi Level in K-Doped Iron Selenide Superconductor.
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Masanori Sunagawa, Kensei Terashima, Takahiro Hamada, Hirokazu Fujiwara, Tetsushi Fukura, Aya Takeda, Masashi Tanaka, Hiroyuki Takeya, Yoshihiko Takano, Masashi Arita, Kenya Shimada, Hirofumi Namatame, Masaki Taniguchi, Katsuhiro Suzuki, Hidetomo Usui, Kazuhiko Kuroki, Takanori Wakita, Yuji Muraoka, and Takayoshi Yokoya
- Abstract
One of the ultimate goals of the study of iron-based superconductors is to identify the common feature that produces the high critical temperature (T
c ). In the early days, based on a weak-coupling viewpoint, the nesting between hole- and electron-like Fermi surfaces (FSs) leading to the so-called s± state was considered to be one such key feature. However, this theory has faced a serious challenge ever since the discovery of alkali-metal-doped FeSe (AFS) superconductors, in which only electron-like FSs with a nodeless superconducting gap are observed. Several theories have been proposed, but a consistent understanding is yet to be achieved. Here we show experimentally that a hole-like band exists in Kx Fe2-y Se2 , which presumably forms a hole-like Fermi surface. The present study suggests that AFS can be categorized in the same group as iron arsenides with both hole- and electron-like FSs present. This result provides a foundation for a comprehensive understanding of the superconductivity in iron-based superconductors. [ABSTRACT FROM AUTHOR]- Published
- 2016
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7. Intrinsic spin polarized electronic structure of CrO2 epitaxial film revealed by bulk-sensitive spin-resolved photoemission spectroscopy.
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Hirokazu Fujiwara, Masanori Sunagawa, Kensei Terashima, Tomoko Kittaka, Takanori Wakita, Yuji Muraoka, and Takayoshi Yokoya
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CHROMIUM oxide ,ELECTRIC properties of metals ,METALLIC thin films ,PHOTOELECTRON spectroscopy ,METALS at low temperatures ,ELECTRON configuration - Abstract
We have performed bulk-sensitive spin-resolved photoemission spectroscopy in order to clarify the intrinsic spin-resolved electronic states of half-metallic ferromagnet CrO
2 . We used CrO2 epitaxial films on TiO2 (100), which shows a peak at 1 eV with a clear Fermi edge, consistent with the bulksensitive PES spectrum for CrO2 . In spin-resolved spectra at 40 K, while the Fermi edge was observed in the spin up (majority spin) state, no states at the Fermi level (EF) with an energy gap of 0.5 eV below EF were observed in the spin down (minority spin) state. At 300 K, the gap in the spin down state closes. These results are consistent with resistivity measurements and magnetic hysteresis curves of the fabricated CrO2 film, constituting spectroscopic evidence for the half-metallicity of CrO2 at low temperature and reducing the spin polarization at room temperature. We also discuss the electron correlation effects of Cr 3d. [ABSTRACT FROM AUTHOR]- Published
- 2015
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8. Signature of high Tc above 25 K in high quality superconducting diamond.
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Hiroyuki Okazaki, Takanori Wakita, Takayuki Muro, Tetsuya Nakamura, Yuji Muraoka, Takayoshi Yokoya, Shin-ichiro Kurihara, Hiroshi Kawarada, Tamio Oguchi, and Yoshihiko Takano
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WIDE gap semiconductors ,NANODIAMONDS ,CHEMICAL vapor deposition ,HIGH temperature superconductors ,DOPED semiconductors ,MAGNETIC susceptibility ,THERMAL conductivity ,DEBYE temperatures - Abstract
We have observed zero resistivity above 10 K and an onset of resistivity reduction at 25.2 K in a heavily B-doped diamond film. However, the effective carrier concentration is similar to that of superconducting diamond with a lower T
c . We found that the carrier has a longer mean free path and lifetime than in the previous report, indicating that this highest Tc diamond has better crystallinity compared to that of other superconducting diamond films. In addition, the susceptibility shows a small transition above 20 K in the high quality diamond, suggesting a signature of superconductivity above 20 K. These results strongly suggest that heavier carrier doped defect-free crystalline diamond could give rise to high Tc diamond. [ABSTRACT FROM AUTHOR]- Published
- 2015
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9. Electronic Structures of CeM2Al10 (M = Fe, Ru, and Os) Studied by Soft X-ray Resonant and High-Resolution Photoemission Spectroscopies.
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Toshihiko Ishiga, Takanori Wakita, Rikiya Yoshida, Hiroyuki Okazaki, Koji Tsubota, Masanori Sunagawa, Kanta Uenaka, Kozo Okada, Hiroshi Kumigashira, Masaharu Oshima, Keisuke Yutani, Yuji Muro, Toshiro Takabatake, Yuji Muraoka, and Takayoshi Yokoya
- Abstract
We have performed a photoemission spectroscopy (PES) study of CeM
2 Al10 (M = Fe, Ru, and Os) to directly observe the electronic structure involved in the unusual magnetic ordering. Soft X-ray resonant (SXR) PES provides spectroscopic evidence of the hybridization between conduction and Ce 4/electrons (c-f hybridization) and the order of the hybridization strength (Ru < Os < Fe). High-resolution (HR) PES of CeRu2 Al10 and CeOs2 Al10 , as compared with that of CeFe2 Al10 , identifies two structures that can be ascribed to structures induced by the c-f hybridization and the antiferromagnetic ordering, respectively. Although the c-f hybridization-induced structure is a depletion of the spectral intensity (pseudogap) around the Fermi level (EF ) with an energy scale of 20-30 meV, the structure related to the antiferromagnetic ordering is observed as a shoulder at approximately 10-11 meV within the pseudogap. The energies of the shoulder structures of CeR2 Al10 and CeOs2 Al10 are approximately half of the optical gap (20meV), indicating that EF is located at the midpoint of the gap. [ABSTRACT FROM AUTHOR]- Published
- 2014
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10. Characteristic two-dimensional Fermi surface topology of high-Tc iron-based superconductors.
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Masanori Sunagawa, Toshihiko Ishiga, Koji Tsubota, Taihei Jabuchi, Junki Sonoyama, Keita Iba, Kazutaka Kudo, Minoru Nohara, Kanta Ono, Hiroshi Kumigashira, Tomohiro Matsushita, Masashi Arita, Kenya Shimada, Hirofumi Namatame, Masaki Taniguchi, Takanori Wakita, Yuji Muraoka, and Takayoshi Yokoya
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FERMI surfaces ,SUPERCONDUCTORS ,IRON ,CRITICAL temperature ,SUPERCONDUCTING transition temperature - Abstract
Unconventional Cooper pairing originating from spin or orbital fluctuations has been proposed for iron-based superconductors. Such pairing may be enhanced by quasi-nesting of two-dimensional electron and hole-like Fermi surfaces (FS), which is considered an important ingredient for superconductivity at high critical temperatures (high-T
c ). However, the dimensionality of the FS varies for hole and electron-doped systems, so the precise importance of this feature for high-Tc materials remains unclear. Here we demonstrate a phase of electron-doped CaFe2 As2 (La and P co-doped CaFe2 As2 ) withTc =45 K, which is the highest Tc found for the AEFe2 As2 bulk superconductors (122-type; AE = Alkaline Earth), possesses only cylindrical hole- and electron-like FSs. This result indicates that FS topology consisting only of two-dimensional sheets is characteristic of both hole- and electron-doped 122-type high-Tc superconductors. [ABSTRACT FROM AUTHOR]- Published
- 2014
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11. Soft X-ray Photoemission Study of New BiS2-Layered Superconductor LaO1-xFxBiS2.
- Author
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Shinsuke Nagira, Junki Sonoyama, Takanori Wakita, Masanori Sunagawa, Yudai Izumi, Takayuki Muro, Hiroshi Kumigashira, Masaharu Oshima, Keita Deguchi, Hiroyuki Okazaki, Yoshihiko Takano, Osuke Miura, Yoshikazu Mizuguchi, Katsuhiro Suzuki, Hidetomo Usui, Kazuhiko Kuroki, Kozo Okada, Yuji Muraoka, and Takayoshi Yokoya
- Abstract
We use core level and valence band soft X-ray photoemission spectroscopy (SXPES) to investigate the electronic structure of new BiS
2 layered superconductor LaO1-x Fx BiS2 . The core level spectra of doped samples show a new spectral feature on the lower binding energy side of the Bi 4f main peak, which may be explained by core-hole screening with metallic states near the Fermi level (EF ). The experimental electronic structure and its x dependence (a higher binding energy shift of the valence band as well as appearance of new states near EF having the dominant Bi 6p character) were found to be consistent with the predictions of band structure calculations in general. Noticeable deviation of the spectral shape of the states near EF from that of calculations might provide insight into interesting physical properties. This study provides the first experimental electronic structure of the new BiS2 layered superconductors. [ABSTRACT FROM AUTHOR]- Published
- 2014
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12. Safe and effective elongation of a short graft and multiple renal veins using the gonadal vein (cylindrical technique) in living donor kidney transplantation
- Author
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Yuki Nakamura, Kaori Dan, Katsuyuki Miki, Takayoshi Yokoyama, Kiho Tanaka, and Yasuo Ishii
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Kidney transplantation ,Gonadal vein ,Laparoscopic donor nephrectomy ,Cylindrical technique ,Surgery ,RD1-811 - Abstract
Background: The use of laparoscopy is increasing in various surgical disciplines, including living donor kidney transplant (LDKT). In laparoscopic transplants, vessel length of the donor kidneys often falls short. This makes anastomosis to the recipient's external iliac vein difficult, which may cause problems when blood circulation reconstruction is required. Renal vein elongation (RVE) is often needed, but the available materials may fall short in terms of post-transplant vessel function. Objective and methods: We aimed to determine whether the gonadal vein was a viable option for RVE in LDKT. We therefore performed LDKT in three cases wherein RVE was performed using the gonadal vein. We used the cylindrical method wherein the donor's gonadal vein was shaped into a cylinder, and the vessel was extended end-to-end with the renal vein. Results: All cases showed immediate graft function after surgery. The total ischemic time was 151, 168, and 169 min in cases 1, 2, and 3, respectively. The serum creatinine levels at discharge were 0.98 mg/dL, 2.07 mg/dL, and 1.16 mg/dL in cases 1, 2, and 3, respectively. None of the patients developed any complications during their hospital stay. Conclusion: Since the renal vein was extended using a gonadal vein, vessel suturing with the external iliac vein became easier; as a result, bleeding and outflow block could be prevented.
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- 2020
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13. Direct observation of double valence-band extrema and anisotropic effective masses of the thermoelectric material SnSe.
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Takanobu Nagayama, Kensei Terashima, Takanori Wakita, Hirokazu Fujiwara, Tetsushi Fukura, Yuko Yano, Kanta Ono, Hiroshi Kumigashira, Osamu Ogiso, Aichi Yamashita, Yoshihiko Takano, Hitoshi Mori, Hidetomo Usui, Masayuki Ochi, Kazuhiko Kuroki, Yuji Muraoka, and Takayoshi Yokoya
- Abstract
Synchrotron-based angle-resolved photoemission spectroscopy is used to determine the electronic structure of layered SnSe, which was recently turned out to be a potential thermoelectric material. We observe that the top of the valence band consists of two nearly independent hole bands, whose tops differ by ∼20 meV in energy, indicating the necessity of a multivalley model to describe the thermoelectric properties. The estimated effective masses are anisotropic, with in-plane values of 0.16–0.39 m
0 and an out-of-plane value of 0.71 m0 , where m0 is the rest electron mass. Information of the electronic structure is essential to further enhance the thermoelectric performance of hole-doped SnSe. [ABSTRACT FROM AUTHOR]- Published
- 2018
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14. Comparative ARPES Study on Iron-Platinum-Arsenide Superconductor Ca10(Pt4As8)(Fe2-xPtxAs2)5 (x = 0.25 and 0.42).
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Masanori Sunagawa, Rikiya Yoshida, Toshihiko Ishiga, Koji Tsubota, Taihei Jabuchi, Junki Sonoyama, Satomi Kakiya, Daisuke Mitsuoka, Kazutaka Kudo, Minoru Nohara, Kanta Ono, Hiroshi Kumigashira, Tamio Oguchi, Takanori Wakita, Yuji Muraoka, and Takayoshi Yokoya
- Abstract
We studied the electronic structure of Ca
10 (Pt4 As8 )(Fe2-x Ptx As2 )5 for two platinum concentrations with different Tc using ARPES. From the carrier number estimated from the areas of FS sheets, we found that the Pt substitution induces electron doping into the Fe2 As2 layers (effectively two electrons per Pt atom). In addition, we found that the FS nesting condition in x = 0.25 is stronger than that in x = 0.42, indicating close correlation between the FS nesting and Tc . [ABSTRACT FROM AUTHOR]- Published
- 2015
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15. Persistent insulator-to-metal transition of a VO2 thin film induced by soft X-ray irradiation.
- Author
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Yuji Muraoka, Hiroki Nagao, Shinsuke Katayama, Takanori Wakita, Masaaki Hirai, Takayoshi Yokoya, Hiroshi Kumigashira, and Masaharu Oshima
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We present a persistent soft-X-ray-induced insulator-to-metal transition at room temperature for VO
2 thin films. Continuous soft X-ray irradiation renders the insulating electronic state metallic in the VO2 thin films, which has been found by photoemission spectroscopy measurement. The observed transition is irreversible and the metallic state persists when soft X-ray irradiation is stopped. The analysis of valence band spectra reveals that the density of states (DOS) of the V 3d band increases with irradiation time, while the DOS of the O 2p band decreases. We propose a simple model where the persistent insulator-to-metal transition is driven by oxygen desorption from VO2 thin films under soft X-ray irradiation. The present results will help in developing a new route for controlling the phase transition of VO2 by light. [ABSTRACT FROM AUTHOR]- Published
- 2014
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16. Proximity to Fermi-surface topological change in superconducting LaO0.54F0.46BiS2.
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Kensei Terashima, Junki Sonoyama, Takanori Wakita, Masanori Sunagawa, Kanta Ono, Hiroshi Kumigashira, Takayuki Muro, Masanori Nagao, Satoshi Watauchi, Isao Tanaka, Hiroyuki Okazaki, Yoshihiko Takano, Osuke Miura, Yoshikazu Mizuguchi, Hidetomo Usui, Katsuhiro Suzuk, Kazuhiko Kuroki, Yuji Muraoka, and Takayoshi Yokoya
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SUPERCONDUCTORS , *PHOTOCONDUCTIVITY , *ELECTRONIC structure , *PHOTOELECTRON spectroscopy , *BINDING energy - Abstract
The electronic structure of nearly optimally doped novel superconductor LaO1-xFxBiS2(x= 0.46) was investigated using angle-resolved photoemission spectroscopy (ARPES). We clearly observed band dispersions from 2 to 6 eV binding energy and near the Fermi level (EF), which are well reproduced by first-principles calculations when the spin-orbit coupling is taken into account. The ARPES intensity map near EF shows a squarelike distribution around the Γ(Z) point in addition to electronlike Fermi-surface (FS) sheets around the X(R) point, indicating that FS of LaO0.54F0.46BiS2 is in close proximity to the theoretically predicted topological change. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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17. Evidence for metallic states in potassium-intercalated picene film on graphite.
- Author
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Hiroyuki Okazaki, Taihei Jabuchi, Takanori Wakita, Takashi Kato, Yuji Muraoka, and Takayoshi Yokoya
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PHOTOELECTRON spectroscopy , *MONOMOLECULAR films , *MATHEMATICAL analysis , *NUCLEAR energy , *ELECTRONIC structure , *CRYSTAL structure , *MATHEMATICAL models - Abstract
We report the results of photoemission spectroscopy on the potassium concentration (x) dependence of Kx picene films on graphite. The results show a systematic shift of a whole valence band and the appearance of a clear Fermi edge for a certain value of x, with additional structures at higher binding energies. Observed spectral evolutions are reminiscent to those of doped C60, implying that the Kx picene film has multiple phases depending on the K concentration. Appearance of a clear Fermi edge, in contrast to multilayer Kx picene films on Au, SiO2, and Ag(111) substrates, where no clear Fermi edges are observed, suggests that the emergence of the metallic states for Kx picene films depends on the specific molecular orientations in the films on different substrates. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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18. Origins of Thermal Spin Depolarization in Half-Metallic Ferromagnet CrO2.
- Author
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Hirokazu Fujiwara, Kensei Terashima, Masanori Sunagawa, Yuko Yano, Takanobu Nagayama, Tetsushi Fukura, Fumiya Yoshii, Yuka Matsuura, Makoto Ogata, Takanori Wakita, Koichiro Yaji, Ayumi Harasawa, Kenta Kuroda, Shik Shin, Koji Horiba, Hiroshi Kumigashira, Yuji Muraoka, and Takayoshi Yokoya
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SPIN polarization , *FERROMAGNETIC materials , *PHOTOELECTRON spectroscopy - Abstract
Using high-resolution spin-resolved photoemission spectroscopy, we observe a thermal spin depolarization to which all spin-polarized electrons contribute. Furthermore, we observe a distinct minority spin state near the Fermi level and a corresponding depolarization that seldom contributes to demagnetization. The origin of this depolarization has been identified as the many-body effect characteristic of half-metallic ferromagnets. Our investigation opens an experimental field of itinerant ferromagnetic physics focusing on phenomena with sub-meV energy scale. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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19. Ce 4f electronic states of CeO1-xFxBiS2 studied by soft x-ray photoemission spectroscopy.
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Takanori Wakita, Kensei Terashima, Takahiro Hamada, Hirokazu Fujiwara, Makoto Minohara, Masaki Kobayashi, Koji Horiba, Hiroshi Kumigashira, Galif Kutluk, Masanori Nagao, Satoshi Watauchi, Isao Tanaka, Satoshi Demura, Hiroyuki Okazaki, Yoshihiko Takano, Yoshikazu Mizuguchi, Osuke Miura, Kozo Okada, Yuji Muraoka, and Takayoshi Yokoya
- Subjects
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PHOTOELECTRON spectroscopy , *X-rays , *SUPERCONDUCTORS - Abstract
We use soft x-ray photoemission spectroscopy (SXPES) to investigate Ce 4f electronic states of a new BiS2 layered superconductor CeO1-xFxBiS2, for polycrystalline and single-crystal samples. The Ce 3d spectrum of the single crystal of nominal composition x=0.7 has no f0 component and the spectral shape closely resembles the ones observed for Ce trivalent insulating compounds, strongly implying that the CeO layer is still in an insulating state even after the F doping. The Ce 3d-4f resonant SXPES for both polycrystalline and single-crystal samples shows that the prominent peak is located around 1 eV below the Fermi level (EF) with negligible spectral intensity at EF. The F-concentration dependence of the valence band spectra for single crystals shows the increases of the degeneracy in energy levels and of the interaction between Ce 4f and S 3p states. These results give insight into the nature of the CeO1-xFx layer and the microscopic coexistence of magnetism and superconductivity in CeO1-xFxBiS2. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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20. Local electronic state in the half-metallic ferromagnet CrO2 investigated by site-selective 53Cr NMR measurements.
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Hikaru Takeda, Yasuhiro Shimizu, Yoshiaki Kobayashi, Masayuki Itoh, Takaaki Jin-no, Masahiko Isobe, Yutaka Ueda, Sho Yoshida, Yuji Muraoka, and Takayoshi Yokoya
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CHROMIUM compounds , *FERROMAGNETIC materials , *NUCLEAR magnetic resonance - Abstract
We have made 53Cr NMR measurements on polycrystalline and single-crystalline film samples to study the local electronic state of a half-metallic ferromagnet CrO2 which has the rutile structure with one crystallographically equivalent Cr site. We observe two kinds of 53Cr NMR spectra in the ferromagnetic state of both the samples. An analysis on the hyperfine field shows the presence of two Cr sites with different orbital occupancies, suggesting that a local orbital order takes place with breaking the local symmetry in the rutile structure. This may be ascribed to the negative charge transfer between chromium and oxygen ions. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
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