{"id":810,"date":"2018-10-03T15:24:12","date_gmt":"2018-10-03T13:24:12","guid":{"rendered":"http:\/\/websrv.saske.sk\/uef\/?page_id=810"},"modified":"2020-02-04T11:45:12","modified_gmt":"2020-02-04T10:45:12","slug":"zameranie","status":"publish","type":"page","link":"https:\/\/websrv.saske.sk\/uef\/oddelenia-a-laboratoria\/laboratorium-nanomaterialov-a-aplikovaneho-magnetizmu\/zameranie\/","title":{"rendered":"Zameranie"},"content":{"rendered":"<p>\nV\u00fdskumn\u00e9 aktivity Oddelenia Aplikovan\u00e9ho Magnetizmu a Nanomateri\u00e1lov (OAMN) s\u00fa zameran\u00e9 na\u00a0 v\u00fdvoj a charakteriz\u00e1ciu nov\u00fdch magnetick\u00fdch materi\u00e1lov s potenci\u00e1lnym vyu\u017eit\u00edm v technickej praxi. Zvl\u00e1\u0161tna pozornos\u0165 je venovan\u00e1 syst\u00e9mom, ktor\u00fdch z\u00e1kladn\u00e9 stavebn\u00e9 jednotky maj\u00fa ve\u013ekos\u0165 1-100 nanometrov.\n<\/p>\n<p>\nV centre n\u00e1\u0161ho dlhodob\u00e9ho z\u00e1ujmu s\u00fa nanokry\u0161talick\u00e9 kovov\u00e9 zliatiny na b\u00e1ze \u017eeleza pripravovan\u00e9 met\u00f3dou kontrolovanej kry\u0161taliz\u00e1cie z amorfn\u00fdch prekurzorov, ktor\u00e9 vykazuj\u00fa okrem vysok\u00fdch hodn\u00f4t magnetickej indukcie i mimoriadne dobr\u00e9 magneticky m\u00e4kk\u00e9 vlastnosti (vysok\u00e1 hodnota permeability a n\u00edzka hodnota koercit\u00edvneho po\u013ea a premagnetiza\u010dn\u00fdch str\u00e1t). T\u00e1to kombin\u00e1cia z nich rob\u00ed atrakt\u00edvne materi\u00e1ly pre vyu\u017eitie vo viacer\u00fdch technick\u00fdch aplik\u00e1ci\u00e1ch ako s\u00fa napr. vysokofrekven\u010dn\u00e9 transform\u00e1tory, magnetick\u00e9 senzory, r\u00f4zne komponenty telekomunika\u010dn\u00fdch a elektronick\u00fdch zariaden\u00ed, magnetick\u00e9 tienenie a in\u00e9. S oh\u013eadom na potenci\u00e1lne vyu\u017eitie t\u00fdchto materi\u00e1lov pri zv\u00fd\u0161en\u00fdch teplot\u00e1ch, zauj\u00edmav\u00e9 v\u00fdsledky boli dosiahnut\u00e9 po substit\u00facii \u010dasti at\u00f3mov \u017eeleza at\u00f3mami kobaltu. V tak\u00fdchto zliatin\u00e1ch sme dosiahli stabilitu dobr\u00fdch magneticky m\u00e4kk\u00fdch vlastnost\u00ed a\u017e do tepl\u00f4t prevy\u0161uj\u00facich 500 \u00b0C a naviac po ich tepelnom spracovan\u00ed v magnetickom poli sme z\u00edskali materi\u00e1l s rekordne n\u00edzkou hodnotou koercit\u00edvneho po\u013ea pre nanokry\u0161talick\u00e9 zliatiny typu HITPERM.\n<\/p>\n<div id=\"attachment_3478\" style=\"width: 360px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-3478\" src=\"http:\/\/websrv.saske.sk\/uef\/wp-content\/uploads\/2019\/12\/LNAM_HRTEM_FeNiNbB.jpg\" alt=\"HRTEM FeNiNbB\" width=\"487\" height=\"495\" class=\"size-full wp-image-3478\" srcset=\"https:\/\/websrv.saske.sk\/uef\/wp-content\/uploads\/2019\/12\/LNAM_HRTEM_FeNiNbB.jpg 487w, https:\/\/websrv.saske.sk\/uef\/wp-content\/uploads\/2019\/12\/LNAM_HRTEM_FeNiNbB-295x300.jpg 295w\" sizes=\"(max-width: 487px) 100vw, 487px\" \/><p id=\"caption-attachment-3478\" class=\"wp-caption-text\">HRTEM sn\u00edmka nanokry\u0161talickej FeNiNbB zliatiny<\/p><\/div>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/websrv.saske.sk\/uef\/wp-content\/uploads\/2019\/12\/LNAM_nanocapsules.jpg\" alt=\"\" width=\"350\" height=\"249\" class=\"aligncenter size-full wp-image-3488\" \/><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/websrv.saske.sk\/uef\/wp-content\/uploads\/2019\/12\/LNAM_Gd_nanoparticle.jpg\" alt=\"\" width=\"350\" height=\"303\" class=\"aligncenter size-full wp-image-3489\" \/><\/p>\n<p>\n\u010cas\u0165 v\u00fdskumn\u00fdch aktiv\u00edt OAMN je venovan\u00e1 magneticky tvrd\u00fdm nanokompozitn\u00fdm zliatin\u00e1m na b\u00e1ze Fe(Co)PtNbB. Za v\u00fdborn\u00e9 magneticky tvrd\u00e9 charakteristiky t\u00fdchto materi\u00e1lov je zodpovedn\u00e1 tetragon\u00e1lna FePt f\u00e1za s extr\u00e9mne vysokou magnetokry\u0161talickou anizotropiou. Magneticky tvrd\u00fd nanokry\u0161talick\u00fd materi\u00e1l na b\u00e1ze FePt vykazuje viac ne\u017e mili\u00f3n kr\u00e1t v\u00e4\u010d\u0161iu hodnotu korcit\u00edvneho po\u013ea v porovnan\u00ed s nanokry\u0161talickou zliatinou na b\u00e1ze FeNi.\n<\/p>\n<p>\nAktivity OAMN s\u00fa orientovan\u00e9 i na v\u00fdvoj nov\u00fdch materi\u00e1lov pre magnetick\u00fa refriger\u00e1ciu. T\u00e1to netradi\u010dn\u00e1 technika chladenia je zalo\u017een\u00e1 na vyu\u017eit\u00ed magnetokalorick\u00e9ho efektu, ktor\u00fd sa prejavuje v adiabatick\u00fdch podmienkach ako zmena teploty materi\u00e1lu v d\u00f4sledku zmeny vonkaj\u0161ieho magnetick\u00e9ho po\u013ea. Ke\u010f je magnetick\u00fd materi\u00e1l vystaven\u00fd p\u00f4sobeniu vonkaj\u0161ieho magnetick\u00e9ho po\u013ea, potom redukcia entropie magnetick\u00fdch spinov m\u00e1 za n\u00e1sledok n\u00e1rast entropie mrie\u017eky, \u010do sa prejav\u00ed rastom teploty. Na druhej strane demagnetiz\u00e1cia materi\u00e1lu m\u00e1 za n\u00e1sledok pokles teploty. Na\u0161e v\u00fdsledky uk\u00e1zali, \u017ee viacer\u00e9 syst\u00e9my ultrajemn\u00fdch superparamagnetick\u00fdch \u010dast\u00edc vykazuj\u00fa perspekt\u00edvne magnetokalorick\u00e9 vlastnosti. Spojen\u00edm spinov do superparamagnetick\u00e9ho klastra, sa magnetick\u00e9 momenty nasmerov\u00e1vaj\u00fa do smeru p\u00f4sobiaceho po\u013ea \u013eah\u0161ie ako u paramagnetick\u00fdch syst\u00e9mov, a pre ur\u010dit\u00e9 hodnoty rozmerov klastrov, po\u013ea a teploty sa entropia spinov m\u00f4\u017ee p\u00f4soben\u00edm vonkaj\u0161ieho po\u013ea \u013eahko meni\u0165. V OAMN s\u00fa vyv\u00edjan\u00e9 nov\u00e9 syst\u00e9my zliatin bohat\u00e9 na prechodov\u00e9 kovy, ktor\u00e9 sa vyzna\u010duj\u00fa relat\u00edvne n\u00edzkou cenou, dobrou chemickou stabilitou a mo\u017enos\u0165ou nastavenia maxim\u00e1lnej odozvy vo\u010di demagnetiz\u00e1cii v \u0161irokom teplotnom intervale \u010do z nich rob\u00ed zauj\u00edmav\u00fdch kandid\u00e1tov pre magnetick\u00e9 chladenie pri izbovej teplote.\n<\/p>\n<p>\nOAMN patr\u00ed medzi zakladaj\u00facich \u010dlenov eur\u00f3pskeho konzorcia GAMAS zameran\u00e9ho na aplik\u00e1ciu magnetick\u00fdch pol\u00ed vo fyzik\u00e1lnom in\u017einierstve. Aktivity laborat\u00f3ria v tomto konzorciu s\u00fa orientovan\u00e9 na tepeln\u00e9 spracovanie materi\u00e1lov v magnetickom poli \u201emagnetick\u00e9 \u017e\u00edhanie\u201c, ktor\u00e9 sa d\u00e1 vyu\u017ei\u0165 pre cielen\u00fa modifik\u00e1ciu funk\u010dn\u00fdch vlastnost\u00ed materi\u00e1lov. Jedn\u00fdm z na\u0161ich konkr\u00e9tnych cie\u013eov v tejto oblasti je v\u00fdvoj nov\u00fdch materi\u00e1lov pre magnetick\u00e9 senzorov\u00e9 syst\u00e9my.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>V\u00fdskumn\u00e9 aktivity Oddelenia Aplikovan\u00e9ho Magnetizmu a Nanomateri\u00e1lov (OAMN) s\u00fa zameran\u00e9 na\u00a0 v\u00fdvoj a charakteriz\u00e1ciu nov\u00fdch magnetick\u00fdch materi\u00e1lov s potenci\u00e1lnym vyu\u017eit\u00edm v technickej praxi. Zvl\u00e1\u0161tna pozornos\u0165&#8230;<\/p>\n","protected":false},"author":4,"featured_media":0,"parent":573,"menu_order":10,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"_links":{"self":[{"href":"https:\/\/websrv.saske.sk\/uef\/wp-json\/wp\/v2\/pages\/810"}],"collection":[{"href":"https:\/\/websrv.saske.sk\/uef\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/websrv.saske.sk\/uef\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/websrv.saske.sk\/uef\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/websrv.saske.sk\/uef\/wp-json\/wp\/v2\/comments?post=810"}],"version-history":[{"count":32,"href":"https:\/\/websrv.saske.sk\/uef\/wp-json\/wp\/v2\/pages\/810\/revisions"}],"predecessor-version":[{"id":3847,"href":"https:\/\/websrv.saske.sk\/uef\/wp-json\/wp\/v2\/pages\/810\/revisions\/3847"}],"up":[{"embeddable":true,"href":"https:\/\/websrv.saske.sk\/uef\/wp-json\/wp\/v2\/pages\/573"}],"wp:attachment":[{"href":"https:\/\/websrv.saske.sk\/uef\/wp-json\/wp\/v2\/media?parent=810"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}