Epsilon iron oxide (ε-Fe<sub>2</sub>O<sub>3</sub>) is a nanoscale iron ox... more Epsilon iron oxide (ε-Fe<sub>2</sub>O<sub>3</sub>) is a nanoscale iron oxide polymorph with a large coercive field value (> 20 kOe at room temperature). High yield ε-Fe<sub>2</sub>O<sub>3</sub> syntheses involve the use of a SiO<sub>2</sub> matrix to prevent agglomeration during high temperature sintering (> 900°C).<sup>1-3</sup> Herein, we present a new synthesis method of ε-Fe<sub>2</sub>O<sub>3</sub> at low temperature and ambient pressure which uses no protective matrix, via a precursor of Prussian blue with a small amount of embedded ε-Fe<sub>2</sub>O<sub>3</sub> nanoparticles.<br/>Core ε-Fe<sub>2</sub>O<sub>3</sub> nanoparticles, prepared using a standard method,<sup>4</sup> were sonicated in K<sub>4</sub>[Fe(CN)<sub>6</sub>]<sub>(aq)</sub> solution before 2M HCl<sub>(aq...
Nitrosyl metal complexes (M-NO), in which nitrosyl ligands are coordinated to transition-metal io... more Nitrosyl metal complexes (M-NO), in which nitrosyl ligands are coordinated to transition-metal ions, have been studied from the viewpoints of physiological activity, catalytic activity, and photosensitivity. The structural flexibility and electric polarization of the nitrosyl ligand are attractive characteristics. Herein we show a photoswitchable nonlinear-optical (NLO) crystal based on a dysprosium-iron nitrosyl assembly. This crystal is composed of a one-dimensional chain structure in the polar Pna21 space group. Because of spontaneous electric polarization, it exhibits a NLO effect of second harmonic generation (SHG). The SHG signal reversibly changes by alternate irradiation with 473 and 804 nm laser lights. The observed photoreversible switching effect on SHG is caused by photoinduced linkage isomerization of the metal nitrosyl sites, i.e., M-N+═O ↔ M-O═N+. Such an optically switchable NLO crystal should be useful for optical devices such as optical filters and optical shutters as well as probes in SHG microscopy.
2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)
Ultrafast magnetic response in epsilon-iron oxide (ε-Fe2O3) nano magnet was measured by terahertz... more Ultrafast magnetic response in epsilon-iron oxide (ε-Fe2O3) nano magnet was measured by terahertz-pump optical Faraday probe measurement. Terahertz excitations induce the extremely fast response of the magnetization. The response time is within 400 fs which corresponds to the time duration of the terahertz pulses.
Nitrosyl metal complexes (M-NO), in which nitrosyl ligands are coordinated to transition-metal io... more Nitrosyl metal complexes (M-NO), in which nitrosyl ligands are coordinated to transition-metal ions, have been studied from the viewpoints of physiological activity, catalytic activity, and photosensitivity. The structural flexibility and electric polarization of the nitrosyl ligand are attractive characteristics. Herein we show a photoswitchable nonlinear-optical (NLO) crystal based on a dysprosium-iron nitrosyl assembly. This crystal is composed of a one-dimensional chain structure in the polar Pna21 space group. Because of spontaneous electric polarization, it exhibits a NLO effect of second harmonic generation (SHG). The SHG signal reversibly changes by alternate irradiation with 473 and 804 nm laser lights. The observed photoreversible switching effect on SHG is caused by photoinduced linkage isomerization of the metal nitrosyl sites, i.e., M-N+═O ↔ M-O═N+. Such an optically switchable NLO crystal should be useful for optical devices such as optical filters and optical shutters as well as probes in SHG microscopy.
Epsilon iron oxide (ε-Fe<sub>2</sub>O<sub>3</sub>) is a nanoscale iron ox... more Epsilon iron oxide (ε-Fe<sub>2</sub>O<sub>3</sub>) is a nanoscale iron oxide polymorph with a large coercive field value (> 20 kOe at room temperature). High yield ε-Fe<sub>2</sub>O<sub>3</sub> syntheses involve the use of a SiO<sub>2</sub> matrix to prevent agglomeration during high temperature sintering (> 900°C).<sup>1-3</sup> Herein, we present a new synthesis method of ε-Fe<sub>2</sub>O<sub>3</sub> at low temperature and ambient pressure which uses no protective matrix, via a precursor of Prussian blue with a small amount of embedded ε-Fe<sub>2</sub>O<sub>3</sub> nanoparticles.<br/>Core ε-Fe<sub>2</sub>O<sub>3</sub> nanoparticles, prepared using a standard method,<sup>4</sup> were sonicated in K<sub>4</sub>[Fe(CN)<sub>6</sub>]<sub>(aq)</sub> solution before 2M HCl<sub>(aq...
Nitrosyl metal complexes (M-NO), in which nitrosyl ligands are coordinated to transition-metal io... more Nitrosyl metal complexes (M-NO), in which nitrosyl ligands are coordinated to transition-metal ions, have been studied from the viewpoints of physiological activity, catalytic activity, and photosensitivity. The structural flexibility and electric polarization of the nitrosyl ligand are attractive characteristics. Herein we show a photoswitchable nonlinear-optical (NLO) crystal based on a dysprosium-iron nitrosyl assembly. This crystal is composed of a one-dimensional chain structure in the polar Pna21 space group. Because of spontaneous electric polarization, it exhibits a NLO effect of second harmonic generation (SHG). The SHG signal reversibly changes by alternate irradiation with 473 and 804 nm laser lights. The observed photoreversible switching effect on SHG is caused by photoinduced linkage isomerization of the metal nitrosyl sites, i.e., M-N+═O ↔ M-O═N+. Such an optically switchable NLO crystal should be useful for optical devices such as optical filters and optical shutters as well as probes in SHG microscopy.
2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)
Ultrafast magnetic response in epsilon-iron oxide (ε-Fe2O3) nano magnet was measured by terahertz... more Ultrafast magnetic response in epsilon-iron oxide (ε-Fe2O3) nano magnet was measured by terahertz-pump optical Faraday probe measurement. Terahertz excitations induce the extremely fast response of the magnetization. The response time is within 400 fs which corresponds to the time duration of the terahertz pulses.
Nitrosyl metal complexes (M-NO), in which nitrosyl ligands are coordinated to transition-metal io... more Nitrosyl metal complexes (M-NO), in which nitrosyl ligands are coordinated to transition-metal ions, have been studied from the viewpoints of physiological activity, catalytic activity, and photosensitivity. The structural flexibility and electric polarization of the nitrosyl ligand are attractive characteristics. Herein we show a photoswitchable nonlinear-optical (NLO) crystal based on a dysprosium-iron nitrosyl assembly. This crystal is composed of a one-dimensional chain structure in the polar Pna21 space group. Because of spontaneous electric polarization, it exhibits a NLO effect of second harmonic generation (SHG). The SHG signal reversibly changes by alternate irradiation with 473 and 804 nm laser lights. The observed photoreversible switching effect on SHG is caused by photoinduced linkage isomerization of the metal nitrosyl sites, i.e., M-N+═O ↔ M-O═N+. Such an optically switchable NLO crystal should be useful for optical devices such as optical filters and optical shutters as well as probes in SHG microscopy.
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