"Lze konstatovat, \u017Ee projekt p\u0159inesl \u0159adu kvalitn\u00EDch experiment\u00E1ln\u00EDch nov\u00FDch poznatk\u016F o manganitech s n\u00E1bojov\u00FDm uspo\u0159\u00E1d\u00E1n\u00EDm typu Mn3+/Mn4+ v r\u016Fzn\u00FDch pom\u011Brech, o nov\u00FDch perovskitech s alkalick\u00FDmi ionty i dal\u0161\u00ED. Obzvl\u00E1\u0161t\u011B zaj\u00EDmav\u00E9 jsou v\u00FDsledky m\u011B\u0159ic\u00ED metod"@cs . . . "We propose a comprehensive study of the manganites with the perovskite structure, in which the Mn3+ and Mn4+ ions coexist. In dependence on the Mn3+ and Mn4+ content, these systems exhibit a variety of phase transitions - structural, as well as magnetic,insulator-metal and charge order. Our attention will be focused on systems with the Mn3+/Mn4+ ratio close to 1:1 and 1:3, in which the proximity of the critical temperatures of the above mentioned phase transitions is expected to cause an unconventionabehavior, leading e.g. to the colossal magnetoresistence or to a change of the crystal structure caused by an applied magnetic field. Hitherto studies of these systems (especially with the 1:3 ratio) are relatively scarce and leave a number of questions open. Experimental part of the project includes preparation of the polycrystalline samples and the single crystals, determination of the crystal and magnetic structures using X-rays and neutrons, measurements of the magnetic moment, electric and therma"@en . "2003-04-01+02:00"^^ . . . . . . . . . "16"^^ . "16"^^ . "P\u0159edkl\u00E1d\u00E1me n\u00E1vrh komplexn\u00EDho studia manganit\u016F s perovskitovou strukturou, v nich\u017E koexistuj\u00ED ionty Mn3+ a Mn4+. V z\u00E1vislosti na obsahu Mn3+ a Mn4+ vykazuj\u00ED tyto syst\u00E9my \u0159adu f\u00E1zov\u00FDch p\u0159echod\u016F strukturn\u00EDho nebo magnetick\u00E9ho charakteru, jako\u017E i typu izol\u00E1tor-kov a uspo\u0159\u00E1d\u00E1n\u00ED n\u00E1boj\u016F. Na\u0161e pozornost bude zam\u011B\u0159ena na syst\u00E9my s pom\u011Brem Mn3+/Mn4+ bl\u00EDzk\u00FDm 1:1 a 1:3, kde lze p\u0159edpokl\u00E1dat, \u017Ee bl\u00EDzkost kritick\u00FDch teplot zm\u00EDn\u011Bn\u00FDch f\u00E1zov\u00FDch p\u0159echod\u016F povede k,neobvykl\u00E9mu chov\u00E1n\u00ED, nap\u0159\u00EDklad ke kolos\u00E1ln\u00ED magnetoresistenci nebo zm\u011Bn\u011B krystalov\u00E9 struktury v d\u016Fsledku p\u0159\u00EDtomnosti vn\u011Bj\u0161\u00ED magnetick\u00E9ho pole.Dosavadn\u00ED pr\u00E1ce na syst\u00E9mech (zejm\u00E9na s pom\u011Brem 1:3) jsou relativn\u011B \u0159\u00EDdk\u00E9 a nech\u00E1vaj\u00ED nezodpov\u011Bzenou \u0159adu ot\u00E1zek. Experiment\u00E1ln\u00ED \u010D\u00E1st projektu zahrnuje p\u0159\u00EDpravu polykrystalick\u00FDch vzork\u016F a monokrystal\u016F, ur\u010Dov\u00E1n\u00ED krystalov\u00FDch a magnetick\u00FDch struktur pomoc\u00ED rentgenov\u00E9ho z\u00E1\u0159en\u00ED a neutron\u016F , m\u011B\u0159en\u00ED magnetick\u00E9ho momentu , elektrick\u00FDch a tepeln\u00FDch vlastnost\u00ED , magnetoresistence a NMR experimenty.Pro pochopen\u00ED" . . "http://www.isvav.cz/projectDetail.do?rowId=GA202/99/0413"^^ . . "GA202/99/0413" . "0"^^ . "Neuvedeno."@en . "Charge ordering, magnetism and the insulator-metal transition in the Mn3+/Mn4+ perovskites"@en . . . "1"^^ . "Uspo\u0159\u00E1d\u00E1n\u00ED n\u00E1boj\u016F, magnetismus a p\u0159echod izol\u00E1tor-kov v Mn3+/Mn4+ perovskitech" . "1"^^ . .