Diamagnetic d-Orbitals Drive Magnetic Structure Selection in the Double Perovskite Ba₂MnTeO₆

Abstract

B-site ordered A2B'B''O6 double perovskites have a variety of applications as magnetic materials.Here we show that diamagnetic d 10 and d 0 B'' cations have a significant effect on the magnetic interactions in these materials. We present a neutron scattering and theoretical study of the Mn 2+ double perovskite Ba2MnTeO6 with a 4d 10 Te 6+ cation on the B''-site. It is found to be a Type I antiferromagnet with a dominant nearest-neighbor J1 interaction. In contrast, the 5d 0 W 6+ analogue Ba2MnWO6 is a Type II antiferromagnet with a significant next-nearest-neighbor J2 interaction. This is due to a d 10 /d 0 effect, where the different orbital hybridization with oxygen 2p results in different superexchange pathways. We show that d 10 B'' cations promote nearest neighbor and d 0 cations promote next-nearest-neighbor interactions. The d 10 /d 0 effect could be used to tune magnetic interactions in double perovskites.

Development of short and long-range magnetic order in the double perovskite based frustrated triangular lattice antiferromagnet Ba$$_{2}$$MnTeO$$_{6}$$

“… indicates the presence of static internal fields, which we attribute to short-range ordering for and long-range ordering for . We note that in BMTO diffuse neutron scattering originating from the same Q positions as spin waves below is found at temperatures far above 37 , therefore our confirmation of the short-range order nicely complements these results. The transverse muon spin relaxation rate (inset in Fig.…”

“…The decrease of the field at site 2 seems to be more enhanced that at site 1, which is probably due to different filtering of magnons at both stoping sites that are unknown for BMTO. At the static internal fields vanish, contrary to the refined magnetic moment deduced from neutron diffraction, which exhibits a smooth evolution across the transition temperature 37 . The fraction of the muon stopping site with the higher internal field value is and is temperature independent.…”

“…Recently, a new B-site ordered double perovskite Ba MnTeO (henceforth BMTO), where Mn ions with spin S = 5/2 constitute a perfect spin lattice without anti-site disorder, has been reported 37 – 39 . While one of the study proposed a cubic space group (Fm m), the other suggested a trigonal space group R m for describing the structure of BMTO 37 , 38 . The same trigonal space group was proposed for the BMTO also in an earlier study 39 .…”

Development of short and long-range magnetic order in the double perovskite based frustrated triangular lattice antiferromagnet Ba2MnTeO6

“…This is a promising candidate to tune electron correlation by quenched disorder in the J 1 -J 2 Heisenberg model on a square lattice. Recently, a new B site ordered double perovskite Ba 2 MnTeO 6 (henceforth BMTO), where Mn 2+ ions with spin S = 5/2 constitute a perfect spin lattice without anti-site disorder, has been reported [35][36][37]. While one of the study proposed a cubic space group (Fm 3m), the other suggested a trigonal space group R 3m for describing the structure of BMTO [35,36].…”

“…Recently, a new B site ordered double perovskite Ba 2 MnTeO 6 (henceforth BMTO), where Mn 2+ ions with spin S = 5/2 constitute a perfect spin lattice without anti-site disorder, has been reported [35][36][37]. While one of the study proposed a cubic space group (Fm 3m), the other suggested a trigonal space group R 3m for describing the structure of BMTO [35,36]. The same trigonal space group has been proposed for the BMTO in an earlier study [37].…”