caa a22 4500 463232690 CHVBK 20180405153247.0 cr unu---uuuuu 170326e20070701xx s 000 0 eng 10.1007/s10853-006-0741-0 doi (NATIONALLICENCE)springer-10.1007/s10853-006-0741-0 Synthesis and physical properties of new oxide AgMnO2 [Elektronische Daten] [Nesrine Koriche, Aissa Bouguelia, Mohamed Mohammedi, Mohamed Trari] A novel oxide AgMnO2 was prepared from LiMnO2 via Ag+→Li+ exchange in the eutectic melt AgNO3-KNO3. It crystallizes in a monoclinically distorted unit cell (SG C2/m) caused by the Jahn-Teller (J-T) ion Mn3+ (3d 4). The structure was refined by isotypy with the crednerite CuMnO2. There are two long axial Mn-O of 264.2(0) pm and four equatorial bonds of 192.7(3) pm and Mn-O-Mn adjoining (83.07°) are bent below the ideal angle. The thermal variation of the magnetic susceptibility (χ/T −1) obeys a Curie-Weiss law with manganese in a trivalent, high spin (HS) state accommodated in elongated MnO6 octahedra (14.8%). Direct coupling between Mn3+ involves negative exchange interactions through long-range antiparallel moments with a temperature θ p =−436K and a magnetic moment of 5.26μB/Mn3+ slightly larger than the spin only moment. The title oxide is stable in air up to ∼680°C before it decomposes into metal silver. It displays a semi-conducting behavior with an activation energy of ∼0.45eV, characteristic of a conduction by low mobility polarons between Ag+/2+ where nearly all polarons are bonded. The photoelectrochemical properties of AgMnO2 have been investigated by photocurrent technique in 1M KOH. The cathodic photocurrent J ph provides unambiguous evidence of p-type character attributed to oxygen insertion (0.025 oxygen by formula unit) as required by the charge compensating mechanism. The valence band is made up of Ag−4d wave functions positioned at ∼5.14 eV below vacuum. A comparison with CuMnO2 was also reported. Springer Science+Business Media, LLC, 2007 Koriche Nesrine Faculté de Chimie, Laboratoire de Stockage et de Valorisation des Energies Renouvelables, USTHB, BP 32, 16111, Algiers, Algeria aut Bouguelia Aissa Faculté de Chimie, Laboratoire de Stockage et de Valorisation des Energies Renouvelables, USTHB, BP 32, 16111, Algiers, Algeria aut Mohammedi Mohamed Ecole Polytechnique EMP, BP 17, Algiers, Algeria aut Trari Mohamed Faculté de Chimie, Laboratoire de Stockage et de Valorisation des Energies Renouvelables, USTHB, BP 32, 16111, Algiers, Algeria aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/13(2007-07-01), 4778-4784 0022-2461 42:13<4778 2007 42 10853 https://doi.org/10.1007/s10853-006-0741-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-006-0741-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Koriche Nesrine Faculté de Chimie, Laboratoire de Stockage et de Valorisation des Energies Renouvelables, USTHB, BP 32, 16111, Algiers, Algeria aut NATIONALLICENCE 700 1- Bouguelia Aissa Faculté de Chimie, Laboratoire de Stockage et de Valorisation des Energies Renouvelables, USTHB, BP 32, 16111, Algiers, Algeria aut NATIONALLICENCE 700 1- Mohammedi Mohamed Ecole Polytechnique EMP, BP 17, Algiers, Algeria aut NATIONALLICENCE 700 1- Trari Mohamed Faculté de Chimie, Laboratoire de Stockage et de Valorisation des Energies Renouvelables, USTHB, BP 32, 16111, Algiers, Algeria aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/13(2007-07-01), 4778-4784 0022-2461 42:13<4778 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer