Structural disorder and magnetic frustration in ALaMnMoO(6) (A=Ba, Sr) double perovskitesстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 29 мая 2015 г.
Аннотация:The crystal and magnetic structures of the ALaMnMoO(6) (A=Ba,Sr) double perovskites have been studied. The Sr compound is monoclinic (space-group P2(1)/n) and does not exhibit long-range magnetic order. The crystal lattice of the Ba compound is pseudocubic, although detailed analysis of neutron diffraction spectra together with the synchrotron diffraction data reveal a slight triclinic distortion (space-group I (1) over bar). The magnitude of the tilting distortion is significantly reduced compared to the Sr compound. Ferrimagnetic order is observed below 80(10) K. The refined Mn moment is 1.35(7)mu(B) at 4 K, suggesting that the ordered moment is reduced by strong frustration effects. This frustration is discussed in terms of competition between nearest-neighbor and next-nearest-neighbor superexchange interactions. Frequency dependent ac susceptibility measurements rule out the existence of a spin-glass state.