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Yokoya T, Terashima K, Takeda A, Fukura T, Fujiwara H, Muro T, Kinoshita T, Kato H, Yamasaki S, Oguchi T, Wakita T, Muraoka Y, Matsushita T. Asymmetric Phosphorus Incorporation in Homoepitaxial P-Doped (111) Diamond Revealed by Photoelectron Holography. Nano Lett 2019; 19:5915-5919. [PMID: 31373825 DOI: 10.1021/acs.nanolett.9b01481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Diamond has two crystallographically inequivalent sites in the unit cell. In doped diamond, dopant occupation in the two sites is expected to be equal. Nevertheless, preferential dopant occupation during growth under nonequilibrium conditions is of fundamental importance, for example, to enhance the properties of nitrogen-vacancy (N-V) centers; therefore, this is a promising candidate for a qubit. However, the lack of suitable experimental techniques has made it difficult to study the crystal- and chemical-site-resolved local structures of dopants. Here, we confirm the identity of two chemical sites with asymmetric dopant incorporation in the diamond structure, via the photoelectron holography (PEH) of heavily phosphorus (P)-doped diamond prepared by chemical vapor deposition. One is substitutionally incorporated P with preferential site occupations and the other can be attributed to a PV split vacancy complex with preferential orientation. The present study shows that PEH is a valuable technique to study the local structures around dopants with a resolution of crystallographically inequivalent but energetically equivalent sites/orientations. Such information provides strategies to improve the properties of dopant related-complexes in which alignment is crucial for sensing of magnetic field or quantum spin register using N-V centers in diamond.
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Affiliation(s)
- T Yokoya
- Research Institute for Interdisciplinary Science (RIIS) , Okayama University , Okayama 700-8530 , Japan
- Graduate School of Science and Technology , Okayama University , Okayama 700-8530 , Japan
| | - K Terashima
- Research Institute for Interdisciplinary Science (RIIS) , Okayama University , Okayama 700-8530 , Japan
| | - A Takeda
- Graduate School of Science and Technology , Okayama University , Okayama 700-8530 , Japan
| | - T Fukura
- Graduate School of Science and Technology , Okayama University , Okayama 700-8530 , Japan
| | - H Fujiwara
- Graduate School of Science and Technology , Okayama University , Okayama 700-8530 , Japan
| | - T Muro
- Japan Synchrotron Radiation Research Institute (JASRI) , 1-1-1 Kouto, Sayo , Hyogo 679-5198 , Japan
| | - T Kinoshita
- Japan Synchrotron Radiation Research Institute (JASRI) , 1-1-1 Kouto, Sayo , Hyogo 679-5198 , Japan
| | - H Kato
- Advanced Power Electronics Research Center , National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba Center 2, Tsukuba , Ibaraki 305-8568 , Japan
| | - S Yamasaki
- Advanced Power Electronics Research Center , National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba Center 2, Tsukuba , Ibaraki 305-8568 , Japan
| | - T Oguchi
- Institute of Scientific and Industrial Research , Osaka University , 8-1 Mihogaoka, Ibaraki , Osaka 567-0047 , Japan
| | - T Wakita
- Research Institute for Interdisciplinary Science (RIIS) , Okayama University , Okayama 700-8530 , Japan
| | - Y Muraoka
- Research Institute for Interdisciplinary Science (RIIS) , Okayama University , Okayama 700-8530 , Japan
- Graduate School of Science and Technology , Okayama University , Okayama 700-8530 , Japan
| | - T Matsushita
- Japan Synchrotron Radiation Research Institute (JASRI) , 1-1-1 Kouto, Sayo , Hyogo 679-5198 , Japan
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Fujiwara H, Terashima K, Sunagawa M, Yano Y, Nagayama T, Fukura T, Yoshii F, Matsuura Y, Ogata M, Wakita T, Yaji K, Harasawa A, Kuroda K, Shin S, Horiba K, Kumigashira H, Muraoka Y, Yokoya T. Origins of Thermal Spin Depolarization in Half-Metallic Ferromagnet CrO_{2}. Phys Rev Lett 2018; 121:257201. [PMID: 30608774 DOI: 10.1103/physrevlett.121.257201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 09/30/2018] [Indexed: 06/09/2023]
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.
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Affiliation(s)
- Hirokazu Fujiwara
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Kensei Terashima
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Masanori Sunagawa
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Yuko Yano
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Takanobu Nagayama
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Tetsushi Fukura
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Fumiya Yoshii
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Yuka Matsuura
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Makoto Ogata
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Takanori Wakita
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Koichiro Yaji
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Ayumi Harasawa
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Kenta Kuroda
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Shik Shin
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Koji Horiba
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801, Japan
| | - Hiroshi Kumigashira
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801, Japan
- Department of Physics, Tohoku University, Sendai, 980-8577, Japan
| | - Yuji Muraoka
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Takayoshi Yokoya
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
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Kita K, Fukura T, Nakase KI, Okamoto K, Yanase H, Kataoka M, Shimizu S. Cloning, overexpression, and mutagenesis of the Sporobolomyces salmonicolor AKU4429 gene encoding a new aldehyde reductase, which catalyzes the stereoselective reduction of ethyl 4-chloro-3-oxobutanoate to ethyl (S)-4-chloro-3-hydroxybutanoate. Appl Environ Microbiol 1999; 65:5207-11. [PMID: 10583966 PMCID: PMC91706 DOI: 10.1128/aem.65.12.5207-5211.1999] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We cloned and sequenced the gene encoding an NADPH-dependent aldehyde reductase (ARII) in Sporobolomyces salmonicolor AKU4429, which reduces ethyl 4-chloro-3-oxobutanoate (4-COBE) to ethyl (S)-4-chloro-3-hydroxybutanoate. The ARII gene is 1,032 bp long, is interrupted by four introns, and encodes a 37,315-Da polypeptide. The deduced amino acid sequence exhibited significant levels of similarity to the amino acid sequences of members of the mammalian 3beta-hydroxysteroid dehydrogenase-plant dihydroflavonol 4-reductase superfamily but not to the amino acid sequences of members of the aldo-keto reductase superfamily or to the amino acid sequence of an aldehyde reductase previously isolated from the same organism (K. Kita, K. Matsuzaki, T. Hashimoto, H. Yanase, N. Kato, M. C.-M. Chung, M. Kataoka, and S. Shimizu, Appl. Environ. Microbiol. 62:2303-2310, 1996). The ARII protein was overproduced in Escherichia coli about 2, 000-fold compared to the production in the original yeast cells. The enzyme expressed in E. coli was purified to homogeneity and had the same catalytic properties as ARII purified from S. salmonicolor. To examine the contribution of the dinucleotide-binding motif G(19)-X-X-G(22)-X-X-A(25), which is located in the N-terminal region, during ARII catalysis, we replaced three amino acid residues in the motif and purified the resulting mutant enzymes. Substrate inhibition of the G(19)-->A and G(22)-->A mutant enzymes by 4-COBE did not occur. The A(25)-->G mutant enzyme could reduce 4-COBE when NADPH was replaced by an equimolar concentration of NADH.
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Affiliation(s)
- K Kita
- Department of Biotechnology, Tottori University, 4-101 Koyama, Tottori 680-8552, Japan.
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