Exchange integrals and magnetization distribution in BaCu2X2O7 (X=Ge,Si)

Sylvain Bertaina (1, 2) , Roland Hayn (1)

1 L2MP - Laboratoire matériaux et microélectronique de Provence
2 LLN - Laboratoire Louis Néel

Estimating the intrachain and interchain exchange constants in BaCu2X2O7 (X=Ge,Si) by means of density-functional calculations within the local spin-density approximation (LSDA) we find the Ge compound to be a more ideal realization of a one-dimensional spin chain with Dzyaloshinskii-Moriya interaction than its Si counterpart. Both compounds have a comparable magnitude of interchain couplings in the range of 5-10 K , but the nearest neighbor intrachain exchange of the Ge compound is nearly twice as large as for the Si one. Using the LSDA+U method we predict the detailed magnetization density distribution and especially remarkable magnetic moments at the oxygen sites.

Mots clés: ab initio; fplo; lsda; copper oxyde; quantum spin chain

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Sylvain Bertaina, Roland Hayn. Exchange integrals and magnetization distribution in BaCu2X2O7 (X=Ge,Si). Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2006, 73, pp.212409. ⟨10.1103/PhysRevB.73.212409⟩. ⟨hal-00084020⟩