Spin-glass transition in the spin\u2013orbit-entangled Jeff\u2009=\u20090 Mott insulating double-perovskite ruthenate

Hayato Yatsuzuka,Akira Matsuo,Koichi Kindo,Hiroko Aruga Katori,Yuya Haraguchi

doi:10.1038/s41598-022-06467-2

Hayato Yatsuzuka, Akira Matsuo + Show 3 more

Open Access

https://doi.org/10.1038/s41598-022-06467-2

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Abstract

We have successfully synthesized new Ru4+ double perovskite oxides SrLaInRuO6 and SrLaGaRuO6, which are expected to be a spin–orbit coupled Jeff = 0 Mott insulating ground state. Their magnetic susceptibility is much significant than that expected for a single Ru4+ ion for which exchange coupling with other ions is negligible. Their isothermal magnetization process suggests that there are about 20 percent isolated spins. These origins would be the Ru3+/Ru5+ magnetic defects, while the regular Ru4+ sites remain nonmagnetic. Moreover, SrLaGaRuO6 shows a spin-glass-like magnetic transition at low temperatures, probably caused by isolated spins. The observed spin-glass can be interpreted by the analogy of a dilute magnetic alloy, which can be seen as a precursor to the mobile Jeff = 1 exciton as a dispersive mode as predicted.

Highlights

MethodsPolycrystalline samples of SrLaMRuO6 (M = In, Ga) were synthesized by the conventional solid-state reaction from stoichiometric mixtures of S rCO3, La2O3, M2O3 (M = In, Ga), and R uO2
We report the magnetic properties of novel double perovskites SrLaInRuO6 and S rLaGaRuO6 with R u4+ ion
The obtained samples were characterized by powder X-ray diffraction (XRD) measurements using a diffractometer with Cu Kα radiation

Summary

Methods

Polycrystalline samples of SrLaMRuO6 (M = In, Ga) were synthesized by the conventional solid-state reaction from stoichiometric mixtures of S rCO3, La2O3, M2O3 (M = In, Ga), and R uO2. The obtained samples were characterized by powder X-ray diffraction (XRD) measurements using a diffractometer with Cu Kα radiation. The cell and crystal structure parameters were refined using the Rietveld method using rietan-fp version 2.16 s oftware[23]. The temperature dependence of the magnetization was measured using the magnetic property measurement system (MPMS; Quantum Design) equipped in the Institute for Solid State Physics at the University of Tokyo. Magnetization curves up to 60 T were measured using an induction method with a multilayer pulsed magnet at the Institute for Solid State Physics at the University of Tokyo

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