{"id":77925,"date":"2015-04-16T15:25:12","date_gmt":"2015-04-16T12:25:12","guid":{"rendered":"http:\/\/www.fyysika.ee\/?p=77925"},"modified":"2015-04-20T15:30:25","modified_gmt":"2015-04-20T12:30:25","slug":"kupraatulijuhid-ei-ole-enam-rekordi-hoidjad","status":"publish","type":"post","link":"https:\/\/www.fyysika.ee\/?p=77925","title":{"rendered":"Kupraat\u00fclijuhid ei ole enam rekordi hoidjad"},"content":{"rendered":"

Kui seni on k\u00f5ige k\u00f5rgema kriitilise temperatuuriga (164K) \u00fclijuhtideks olnud kupraadid, siis n\u00fc\u00fcd on sellele positsioonile t\u00f5usmas k\u00f5rgel r\u00f5hul (200GPa) vesiniksulfiid, mis muutub \u00fclijuhiks juba 190K juures. Selline avastus on pikk samm toatemperatuursete \u00fclijuhtivate materjalide poole. Uued teoreetilised arvutused n\u00e4itavad, et vesiniksulfiidi \u00fclijuhtivust on v\u00f5imalik seletada tavap\u00e4rase \u00fclijuhtivuse\u00a0teooria raames, st elektronide paaride moodustumise kaudu.<\/p>\n

\"1024px-Hydrogen-sulfide-3D-balls\"<\/a>

Vesiniksulfiidi molekul normaalr\u00f5hul.<\/p><\/div>\n

Kui te v\u00f5tate lahti m\u00f5ne teatmeteose v\u00f5i vikipeedia, siis saate teada, et vesiniksulfiid ehk divesiniksulfiid ehk\u00a0v\u00e4\u00e4velvesinik\u00a0(H2<\/sub>S) on m\u00e4damuna l\u00f5hnaga, \u00f5hust raskem v\u00e4rvuseta ja m\u00fcrgine gaas. Kusjuures \u00f5hu juuresolekul vesiniksulfiid p\u00f5leb. Mismoodi saab vesiniksulfiid olla \u00fclijuht, st juhtida elektrivoolu, pealegi ilma takistuseta?<\/p>\n

Siin tuleb j\u00e4lle kord nentida, et loodus on h\u00e4mmastavalt mitmetahuline. Panete kindlasti t\u00e4hele, et vesiniksulfiidi molekul on \u00fcsna sarnane struktuuriga, kui vee molekul? Kas teate, mis olekus on vesi v\u00e4ga k\u00f5rgetele r\u00f5hkudel?\u00a0\u00d5ige vastus on, et vesi v\u00f5ib olla ka metalliline.<\/p>\n

\"H2Sfaasid\"<\/a>

Vesiniksulfiidi faasidiagramm, nagu seda tunti 1995.a, vt PhysRevB.51.9391<\/p><\/div>\n

Vesiniksulfiid on seega sama h\u00e4mmastav materjal, kui vesi. Ka temal on mitmeid erinevaid faase. Ja 200GPa r\u00f5hu juures on vesiniksulfiid metalliline\u00a0ja\u00a0muutub 190K, st -83 kraadi juures \u00fclijuhiks. Kusjuures struktuur on tal siis hoopis selline, kui n\u00e4itab alumine joonis.<\/p>\n

\u00dclijuhtide teooria on keeruline\u00a0ja\u00a0selle lihtsustatud kujul \u00fcmberjutustamiseks peab olema v\u00e4ga vinge selle ala spetsialist … eriti kui arvestada, et kupraatide \u00fclijuhtivuse teooria ei ole ka spetsialistidele\u00a0l\u00f5puni selge, ehkki uuritud on seda juba peaaegu 30 aastat. Ehk oleme tulevikus targemad ja v\u00f5tame selle teema uuesti ette.<\/p>\n

\"srep06968-f6\"

K\u00f5rgel r\u00f5hul on vesiniksulfiid metalliline. Arvutused n\u00e4itavad, et 200GPa r\u00f5hu juures on k\u00f5ige stabiilsem pildil n\u00e4ha oleva struktuuriga kirstall, mida t\u00e4histatakse Im-3m. Vasakul on n\u00e4ha kristalli struktuur, paremal \u00fcks selle l\u00f5igetest. Joonis: Nature<\/p><\/div>\n

 <\/p>\n

Allikad:<\/p>\n

http:\/\/physics.aps.org\/synopsis-for\/10.1103\/PhysRevLett.114.157004<\/a><\/p>\n

http:\/\/arxiv.org\/ftp\/arxiv\/papers\/1412\/1412.0460.pdf<\/a><\/p>\n

http:\/\/www.nature.com\/srep\/2014\/141110\/srep06968\/full\/srep06968.html<\/a><\/p>\n

http:\/\/journals.aps.org\/prb\/abstract\/10.1103\/PhysRevB.51.9391<\/a><\/p>\n

http:\/\/www1.lsbu.ac.uk\/water\/water_phase_diagram.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Kui seni on k\u00f5ige k\u00f5rgema kriitilise temperatuuriga (164K) \u00fclijuhtideks olnud kupraadid, siis n\u00fc\u00fcd on sellele positsioonile t\u00f5usmas k\u00f5rgel r\u00f5hul (200GPa) vesiniksulfiid, mis muutub \u00fclijuhiks juba 190K juures. Selline avastus on pikk samm toatemperatuursete \u00fclijuhtivate materjalide poole. Uued teoreetilised arvutused n\u00e4itavad, et vesiniksulfiidi \u00fclijuhtivust on v\u00f5imalik seletada tavap\u00e4rase \u00fclijuhtivuse\u00a0teooria raames, st elektronide paaride moodustumise kaudu. Kui […]<\/p>\n","protected":false},"author":1,"featured_media":78228,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[16],"tags":[],"class_list":{"0":"post-77925","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-teadusuudis","8":"entry"},"_links":{"self":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/77925","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=77925"}],"version-history":[{"count":0,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/77925\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/media\/78228"}],"wp:attachment":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=77925"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=77925"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=77925"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}