Near compensated half-metal in Sr2NiOsO6

Abstract

The electronic and magnetic properties of tetragonal double perovskite Sr(2)NiOsO(6) were studied by use of the density functional theory and including the spin-orbit coupling. Compensated half-metal is found if the spin-orbit coupling is not considered. Spin-orbit coupling induces orbital moments on both Ni and Os, making Sr(2)NiOsO(6) a near compensated half-metal. Ferromagnetic phase is slightly favored over antiferromagnetic phase (by 4 meV). The small energy difference also suggests that both phases are competitive for the ground state. At ferromagnetic phase, the calculated net magnetic moment is 3.53 micro(B), in good agreement with experimental value of 3.44 micro(B). At antiferromagnetic phase, the net magnetic moment is 0.69 micro(B), in which the contribution from the net spin moment is 0.09 micro(B).

Evaluation of half-metallic antiferromagnetism inA2CrFeO6(A<

“…The DP of A 2 BB ′ O 6 (A= La or Sr) has a rock-salt structure of transition metals BB ′ . 5 In spite of many predictions of CHM in DP-related compounds, 4,[6][7][8][9][10][11][12][13][14] no experimental evidence has been observed. The reasons for this are not yet clear, but some seem to result from antisite disorder on B and B ′ sites.…”

The influence of electron correlation and spin–orbit coupling on the half metallic properties of LaSrMoReO6, LaSrMoTcO6 and LaSrVOsO6

“…In the previous studies, we noticed that various U values are chosen for the two transition metals. For V, they are around 4.0 eV in SrVO 3 [15], 3.5 and 5.0 eV in MnV 2 O 4 [16] as well as larger than 3.3 eV in SrVO 3 and CaVO 3 [17]; while for Os, they are 0.5 eV in Sr 2 CrOsO 6 [4], 2.0 eV in Sr 2 NiOsO 6 [5], 1.5-2.0 eV [20] and 2.7 eV [19] in Ba 2 NaOsO 6 . This means that of our choice of U V = 4.0 eV and U Os = 2.5 eV is acceptable.…”

“…It was indeed found that they are good candidates for CHM by using the generalized gradient approximation (GGA) method without the inclusion of the SOC effect and electron correlation [6]. However, it has been well established that the electron correlation is important for V [15][16][17], Mo [18], Os [4,5,19,20] and Re [21,22]. In addition, for transition metal atoms, in particular 4d and 5d atoms, the SOC effect is known to be large.…”

“…On the other hand, the previous studies also showed that spin-orbit coupling will also affect (mainly destroys) the half metallic characters. For instance, the recent theoretical studies on Sr 2 CrOs-O 6 (Cr 3+ , t 2g 3 ;, S = 3/2; Os 5+ , t 2g 3 ", S = 3/2) [4] and Sr 2 NiOsO 6 (Ni 2+ , t 2g 6 e g 2 ;, S = 1; Os 6+ , t 2g 2 ", S = 1) [5] indicated that the spin moments can cancel exactly, but total orbital moments are 0.54 and 0.60 l B , respectively, indicating that due to the involvement of SOC, the compensation of the magnetic moments is not exact, i.e., the two compounds are ferrimagnetic half metals.…”

“…There is no experimental evidence for CHM to date. Therefore, the searching for materials with CHM character is a hot topic [2][3][4][5][6][7][8][9][10][11][12][13][14]. Recently, there have been several reports for CHM from double perovskites.…”