Dresden 2014 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 55: Poster II

MA 55.76: Poster

Freitag, 4. April 2014, 10:30–13:30, P2

Magnetic property of Mixed valent Sodium Sequioxide (Na2O3) — •Shivakumara Giriyapura, Sergiy Medvediev, Martin Jansen, and Claudia Felser — MPI-CPFS, 01187, Dresden

It is well-known that compounds containing mixed diatomic oxygen species (superoxide (O2-) is magnetic and peroxide (O22-) diamagnetic) can be stabilized in different forms of A2O2 , A2O3, AO2 and AO2-x [1,3] (A = alkaline metals). Consequently, it is been realized that alkali superoxides (A+O2-) containing magnetic diatomic O2- ions behave like strongly correlated transition metal compounds, where the displacive Jahn-Teller distortion lifts the degeneracy and leads to the reorientation of diatomic anions (O2-) with corresponding orbital ordering (OO) [2][3]. Similarly, mixed valent A4O6 reveals a mixture of superoxide O2- and peroxide O22- with different valency which can lead to a charge ordered state in the lattice. Charge order (CO) is known to be in competition with superconductivity. Accordingly, its been synthesized the Sodium sesquioxide (Na2O3) and discussed the structural and magnetic studies of this compound in comparison with the magnetic end member NaO2 and rest of the alkali sesquioxide(A4O6. [1] W. Hesse, M. Jansen and W. Schnick, Prog. Solid St. Chem. Vol. 19, pp. 47-110. 1989.[2] S. Riyadi, B. Zhang, R. A de Groot, A. Caretta, P.H.M. van Loosdrecht, T. T. M. Palstra and G.R.Blake, Phys. Rev. Lett. 108, (2012) 217206.[3] S.Riyadi, S.Giriyapura, R.A. de Groot, A.Caretta, P.H. M. van Loosdrecht, T. T. M. Palstra, and G. R. Blake. Chem. Mater. 2011, 23, 1578*1586.