{"created":"2023-06-19T10:30:13.579685+00:00","id":10447,"links":{},"metadata":{"_buckets":{"deposit":"4f8aa0eb-9ac4-41c6-9d8f-9ffd2155e9d2"},"_deposit":{"created_by":18,"id":"10447","owners":[18],"pid":{"revision_id":0,"type":"depid","value":"10447"},"status":"published"},"_oai":{"id":"oai:muroran-it.repo.nii.ac.jp:00010447","sets":["41:227"]},"author_link":["58502"],"item_81_date_granted_17":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2021-03-23"}]},"item_81_degree_grantor_10":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_language":"ja","subitem_degreegrantor_name":"室蘭工業大学"},{"subitem_degreegrantor_language":"en","subitem_degreegrantor_name":"Muroran Institute of Technology"}],"subitem_degreegrantor_identifier":[{"subitem_degreegrantor_identifier_name":"10103","subitem_degreegrantor_identifier_scheme":"kakenhi"}]}]},"item_81_degree_name_11":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士（工学）","subitem_degreename_language":"ja"}]},"item_81_description_25":{"attribute_name":"フォーマット","attribute_value_mlt":[{"subitem_description":"application/pdf","subitem_description_type":"Other"}]},"item_81_description_7":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"希土類単硫化物はNaCl型の結晶構造をもち，光学デバイス，太陽電池，フォトダイオード，磁気記録デバイスなどのエレクトロニクス分野における応用に不可欠な材料である。しかし，希土類金属と硫黄の蒸気圧が大きく異なる点，単体の希土類金属が極めて酸化しやすい点，これまでの試料作製方法が非常に多くの反応プロセスを伴う複雑なものであることなどから，純良な希土類単硫化物試料の合成は困難であった。本研究では，これまで研究例のほとんどない，Gd, Ho を含む希土類単硫化物に着目し，CS2ガス硫化法により作製した希土類三二硫化物（α-Gd2S3, δ-Ho2S3）と希土類単体（Ho）もしくは希土類水素化物（GdH2）を出発物質とし，放電プラズマ焼結（SPS）装置を用いた反応焼結法により，物性測定が可能である大きなサイズの希土類単硫化物GdS, HoSの純良な単一相焼結体の合成に成功した。また，出発原料の希土類と硫黄の比率を変えることにより，非化学量論比組成のGdSx，HoSxの単一相焼結体を広い組成範囲で合成することにも成功した。さらに，得られた試料について，結晶構造解析，元素組成分析，微量に含まれる不純物の同定を行い，熱物性，電子物性を詳細に調べた。その結果，格子定数，融点，電気伝導率の変化が，希土類と硫黄の組成比（x）と密接に関係していることを確認した。本研究では，従来の方法よりも単純なプロセスで不純物の少ない純良な希土類単硫化物の大型焼結体の合成が可能であることを示した。さらに，出発原料の比率を変えることで，非化学量論比組成の希土類単硫化物における希土類と硫黄の組成比（x）を制御することが可能であることを示した。さらに，希土類と硫黄の組成比（x）を変えることで電気伝導率などの物性を大きく変化させることが可能であることから，今回得られた結果は，物性値の最適化を行う上でも重要な知見であると考えられる。これらの結果は，Gd, Ho以外の希土類単硫化物にも応用が可能であると考えられ，今後の希土類単硫化物の設計の幅を広げることにつながり，次世代の高性能デバイスに不可欠な材料開発の発展に寄与するものであると考えられる。","subitem_description_language":"ja","subitem_description_type":"Abstract"},{"subitem_description":"Rare-earth monosulfides RES (RE=rare earth element) with NaCl structure have various practical and potential applications in the electronics field, such as optical devices, photovoltaics, photodiodes, and magnetic recording devices. However, the synthesis of high-quality RES samples remains a challenge because RE is easily oxidized, large difference between the vapor pressures of RE and S, and the complexity of the previous synthesis methods. In this study, we focused on rare-earth monosulfides containing Gd and Ho, on which few studies have been done so far. Using rare-earth sesquisulfides (-Gd2S3, -Ho2S3) prepared by the CS2 gas sulfurization process and Ho metal or GdH2 as a starting material, we have succeeded in synthesizing single-phase GdS and HoS compacts of large size that we can measure their physical properties, by reaction sintering method using a spark plasma sintering (SPS) device. We have also succeeded in synthesizing single-phase GdSx and HoSx compacts with non-stoichiometric ratio composition in a wide composition range by changing the ratio of Gd (or Ho) and S as starting materials. Furthermore, for the obtained samples, crystal structure, elemental composition, identification of impurity phases, thermal properties and electronic properties were investigated in detail. As a result, it was confirmed that changes in lattice constant, melting point, and electrical conductivity are closely related to the composition ratio (x) of RE and S. In this study, we showed that it is possible to synthesize large compacts of pure rare-earth monosulfides with less impurities by a simpler process than the conventional method. Furthermore, it was shown that the composition ratio (x) of RE and S in rare-earth monosulfides with non-stoichiometric ratio composition can be controlled by changing the ratio of starting materials and we can significantly change physical properties such as electrical conductivity by changing the composition ratio (x) of RE and S. Therefore, the results are important for optimizing physical properties. These results are also considered to be applicable to rare-earth monosulfides other than Gd and Ho, which will lead to a wider range of designs for rare-earth monosulfides. It is considered to contribute to develop materials for next-generation high-performance devices.\n","subitem_description_language":"en","subitem_description_type":"Abstract"}]},"item_81_dissertation_number_13":{"attribute_name":"学位授与番号","attribute_value_mlt":[{"subitem_dissertationnumber":"甲第461号"}]},"item_81_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15118/00010386","subitem_identifier_reg_type":"JaLC"}]},"item_81_subject_9":{"attribute_name":"日本十進分類法","attribute_value_mlt":[{"subitem_subject":"436","subitem_subject_scheme":"NDC"}]},"item_81_text_12":{"attribute_name":"学位の種別","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"課程博士"}]},"item_81_text_14":{"attribute_name":"報告番号","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"甲第461号"}]},"item_81_text_15":{"attribute_name":"学位記番号","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"博甲第461号"}]},"item_81_text_16":{"attribute_name":"研究科・専攻","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"工学専攻"}]},"item_81_version_type_24":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_access_right":{"attribute_name":"アクセス権","attribute_value_mlt":[{"subitem_access_right":"open access","subitem_access_right_uri":"http://purl.org/coar/access_right/c_abf2"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorAffiliations":[{"affiliationNameIdentifiers":[],"affiliationNames":[{"affiliationName":"","affiliationNameLang":"ja"}]}],"creatorNames":[{"creatorName":"TRAN, Nhu Bien","creatorNameLang":"en"},{"creatorName":"チャン, ヌ ヴィエン","creatorNameLang":"ja"}],"familyNames":[{"familyName":"TRAN","familyNameLang":"en"},{"familyName":"チャン","familyNameLang":"ja"}],"givenNames":[{"givenName":"Nhu Bien","givenNameLang":"en"},{"givenName":"ヌ ヴィエン","givenNameLang":"ja"}],"nameIdentifiers":[{"nameIdentifier":"58502","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2021-06-23"}],"displaytype":"detail","filename":"A461.pdf","filesize":[{"value":"8.8 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"A461","objectType":"fulltext","url":"https://muroran-it.repo.nii.ac.jp/record/10447/files/A461.pdf"},"version_id":"5cf0bc67-9478-4206-8816-a3696383eaf3"},{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2021-06-23"}],"displaytype":"detail","filename":"A461_summary.pdf","filesize":[{"value":"338.4 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"A461_summary","objectType":"abstract","url":"https://muroran-it.repo.nii.ac.jp/record/10447/files/A461_summary.pdf"},"version_id":"129ba5a3-04c3-4290-bd7e-775cacd2a712"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"doctoral thesis","resourceuri":"http://purl.org/coar/resource_type/c_db06"}]},"item_title":"Synthesis of rare-earth mono-sulfides RESx (RE=Gd, Ho) compacts by reaction Sintering","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Synthesis of rare-earth mono-sulfides RESx (RE=Gd, Ho) compacts by reaction Sintering","subitem_title_language":"en"},{"subitem_title":"反応焼結法による希土類単硫化物 RESx 　(RE = Gd, Ho)の合成","subitem_title_language":"ja"}]},"item_type_id":"81","owner":"18","path":["227"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2021-06-23"},"publish_date":"2021-06-23","publish_status":"0","recid":"10447","relation_version_is_last":true,"title":["Synthesis of rare-earth mono-sulfides RESx (RE=Gd, Ho) compacts by reaction Sintering"],"weko_creator_id":"18","weko_shared_id":-1},"updated":"2024-01-22T01:59:18.691715+00:00"}