Magnetization density distribution in the metallic ferromagnet SrRuO3 determined by polarized neutron diffraction

Abstract

The magnetization-density distribution in the metallic ferromagnet SrRuO3 was studied by means of polarized neutron diffraction. The analyzes by multipole refinements and by the maximum entropy method consistently reveal a strong polarization of all oxygen sites carrying 30% of the total magnetization. The spin-density distribution on the Ru site exhibits a nearly cubic shape in agreement with an almost equal occupation of t2g orbitals and pd hybridization. The experimental analysis is well reproduced by density functional calculations. There is no qualitative change in the magnetization distribution between 2 and 200 K

Underlying Mechanisms and Tunability of the Anomalous Hall Effect in NiCo2O4 Films with Robust Perpendicular Magnetic Anisotropy

“…Despite the strong spin fluctuations near T C , [ 33 ] the temperature dependence of ρ A can be well fitted by a power law ( T C − T ) γ (red line) with an obtained exponent of γ ≈ 0.2 to 0.4 (see also in Figure , Supporting Information), following the behavior of the magnetization commonly observed for ferro‐ and ferrimagnetic materials. [ 50,51 ] Consequently, the deviation between ρ A and ρ xx in this range is mainly due to the decreasing magnetization, which predominantly affects the AHE. (iv)Non‐magnetic or paramagnetic regime T > T C in which the AHE vanishes along with the magnetization whereas ρ xx remains finite. [ 52 ] …”

Oxygen magnetic polarization, nodes in spin density, and zigzag spin order in oxides

“…Recently, another the-oretical work suggested that a simplified super-superexchange is inappropriate for the description of the BCO system, because the magnetic moment of oxygens was also considered to provide a substantial contribution to the total local magnetic moments of each CoO 4 ionic cluster [44]. Furthermore, their density functional theory (DFT) calculations also unveiled another interesting finding: the spin density exhibits a node between O and Co atoms, and a similar phenomenon was also found in SrRuO 3 [28,44].…”

“…Experimental results for SrRuO 3 [28] showed that oxygens carry a finite magnetic moment when the Ru spins are in a ferromagnetic state. The recent efforts in Ba 2 CoO 4 [44] have reached similar conclusions using DFT, namely the presence of a magnetic moment at the oxygens, but now in a global long-range zigzag antiferromagnetic state (discussed more extensively in the next section) instead of the FM state of SrRuO 3 .…”

“…However, a recent polarized neutron diffraction experiment unveiled the surprising fact that a strong magnetic polarization is present in all oxygen sites -contributing 30% of the total magnetization -in the case of the metallic ferromagnet SrRuO 3 [28]. Previous studies also found a nonzero magnetization density at the oxygen ions in the yttrium iron garnet [29], Li 2 CuO 2 [30], La 0.8 Sr 0.2 MnO 3 [31], YTiO 3 [32], and Ca 1.5 Sr 0.5 RuO 4 [33].…”

Thermopower in the Ba1−δM2+xRu4−xO11<

“…Electronic and magnetic properties can be strongly modified in these ruthenium oxides, depending on the crystallographic structure, where 3D or 2D layers have more or less tilted RuO 6 octahedra. Among the most investigated properties, superconductivity and strong magnetic fluctuations in Sr 2 RuO 4 [1,2], and a transition from paramagnetism (PM) to ferromagnetism (FM) when going from CaRuO 3 to SrRuO 3 metallic perovskites have been studied in detail [3][4][5][6]. Interestingly, the thermopower in these ruthenates has been reported to exhibit a nontrivial behavior with positive values, increasing up to high T and reaching a value close to +20-30 μV K -1 at T 300 K, independently of the transport and magnetic properties [7][8][9][10].…”