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- Giorgianni, Flavio, et al.
(author)
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Melting of magnetic order in NaOsO3 by femtosecond laser pulses
- 2022
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In: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 105:15
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Journal article (peer-reviewed)abstract
- NaOsO3 has recently attracted significant attention for the strong coupling between its electronic band structure and magnetic ordering. Here, we used time-resolved magnetic x-ray diffraction to determine the timescale of the photoinduced antiferromagnetic dynamics in NaOsO3. Our measurements are consistent with a sub-100 fs melting of the antiferromagnetic long-range order that occurs significantly faster than the lattice dynamics as monitored by the transient change in intensity of selected Bragg structural reflections, which instead show a decrease of intensity on a timescale of several ps.
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2. |
- Janousch, Markus, et al.
(author)
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Role of oxygen vacancies in cr-doped SrTiO3 for resistance-change memory
- 2007
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In: Advanced Materials. - Weinheim : Wiley-VCH Verlagsgesellschaft. - 0935-9648 .- 1521-4095. ; 19:17, s. 2232-2235
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Journal article (peer-reviewed)abstract
- A high density of oxygen vacancies has been found in an experiment to determine the path of electrical conduction in Cr-doped SrTiO3 memory cells. The Cr acts as a seed for the localization of oxygen vacancies, leading to a statistically homogeneous distribution of charge carriers within the path. This warrants a controllable doping profile and improved device scaling down to the nanometer scale. The combination of laterally resolved micro-X-ray absorption spectroscopy and thermal imaging concludes that the resistance switching in Cr-doped SrTiO3 originates from an oxygen-vacancy drift to/from the electrode that was used as anode during the conditioning process. The experiments shows that this oxygen vacancy concept is crucial for the entire class of transition-metal-oxide-based bipolar resistance-change memory.
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3. |
- Parchenko, Sergii, et al.
(author)
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Orbital dynamics during an ultrafast insulator to metal transition
- 2020
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In: Physical Review Research. - : AMER PHYSICAL SOC. - 2643-1564. ; 2:2
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Journal article (peer-reviewed)abstract
- We present ultrafast resonant inelastic x-ray scattering (RIXS) experiments performed at the vanadium L edge to track changes in the electronic structure of V2O3, a classical Mott-Hubbard material. The probed orbital excitations within the d shell of the V ion show a sub-ps time response, which evolves at later times to a state that appears electronically indistinguishable from the high-temperature metallic state. For low excitation fluences, a transient recovery or delay is observed, which could be related to a transient dimerization of the V-V bonds. Our results demonstrate the great potential for RIXS spectroscopy to study the ultrafast orbital dynamics in strongly correlated materials.
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