. "0"^^ . . . . . . . . "U manganit\u016F Pr1-yNayMn1-xCoxO3 a Pr0.46Sr0.54Mn0.96Cr0.04O3 s vhodn\u00FDmi magnetick\u00FDmi a elektrick\u00FDmi vlastnostmi, byly pro teploty 10-250 K zji\u0161t\u011Bny vratn\u00E9 a nevratn\u00E9 fotoindukovan\u00E9 p\u0159echody izol\u00E1tor-kov s v\u00FDrazn\u00FDmi zm\u011Bnami el. odporu."@cs . "2"^^ . "2004-10-27+02:00"^^ . . "0"^^ . . . . . "http://www.isvav.cz/projectDetail.do?rowId=IAA1010004"^^ . . "U manganat\u00FDch perovskit\u016F LN(1-x)AxMnO3 lze pro koncentrace Mn3+/Mn4+bl\u00EDzk\u00E9 1:1 vyvolat r\u016Fzn\u00FDmi vlivy, ku p\u0159\u00EDkladu magnetick\u00FDm polem nebo vysok\u00FDm tlakem p\u0159echod ze z\u00E1kladn\u00EDho antiferomagnetick\u00E9ho izola\u010Dn\u00EDho stavu do feromanetick\u00E9ho kovov\u00E9ho stavu. Z praktick\u00E9ho hlediska je v\u00FDznamn\u00E1 mo\u017Enost lok\u00E1ln\u00ED indukce tohoto p\u0159echodu do kovov\u00E9ho stavu oz\u00E1\u0159en\u00EDm rentgenov\u00FDmi paprsky nebo viditeln\u00FDm sv\u011Btlem, zat\u00EDmco okoln\u00ED materi\u00E1l si zachov\u00E1v\u00E1 izola\u010Dn\u00ED charakter. Projekt je zam\u011B\u0159en na novou t\u0159\u00EDdu t\u011Bchto l\u00E1tek, zalo\u017Een\u00FDch na substituci alkalick\u00FDch kov\u016F, kter\u00E9 vykazuj\u00ED podobn\u00FD efekt. V\u00FDzkum bude zahrnovat p\u0159\u00EDpravu t\u011Bchto l\u00E1tek v polykrystalick\u00E9 i monokrystalick\u00E9 form\u011B a jejich kompl. fyzik\u00E1ln\u00ED a chemickou charakterizaci s c\u00EDlem p\u0159\u00EDpravy materi\u00E1l\u016F pro opticky \u0159\u00EDzen\u00E9 elektronick\u00E9 elementy." . "9"^^ . "manganese perovskites inzulator-metal transition photoinduced effects"@en . "Oxidov\u00E9 materi\u00E1ly s fotoindukovan\u00FDm p\u0159echodem izol\u00E1tor - kov" . "9"^^ . "IAA1010004" . . . "The charge ordered antiferromagnetic insulating groundstate of perovskite manganites Ln(1-x)AxMnO3 in the concentration range of Mn3+/Mn4+ close to 1:1 can be transformed to a metallic ferromagnetic state by magnetic field, high pressure or other means. It is of great practical importance that the metallic state can be induced locally by illumination with X rays or visible light while surrouding material remains insultating. This project is directed to novel class of manganites based on alkali metal substitutions which show similar effect. The research will involve the preparation of samples by ceramic methods and growth of single crystals from high temperature solutions. A complex physical and chemical characterization will be undertaken with the aim to prepare materials for optically switched electronic elements."@en . . "Oxidic materials with photoinduced insulator-metal transition"@en . .