Infrared microspectroscopy station at BL43IR of SPring-8

Ikemoto, Yuka; Moriwaki, Toshimichi; Hirono, T.; Kimura, S.; Shinoda, Keiji; Matsunami, Masaharu; Nagai, Naoto; Nanba, Tetsuya; Kobayashi, Kimihiro; Kimura, Hiroaki

doi:10.1016/j.infrared.2004.01.004

Cited by 44 publications

(26 citation statements)

References 8 publications

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“…Due to the small size of the sample and the restricted sample space in a DAC, synchrotron radiation was used as a highly oriented and bright infrared (IR) source. The high pressure studies were made mainly at the beam line BL43IR of SPring-8 22,23 at photon energies between 20 meV and 1.1 eV. Above 1.1 eV, the reflectance at ambient temperature and pressure 3 was used.…”

Section: Methodsmentioning

confidence: 99%

Pressure suppression of unconventional charge-density-wave state in PrRu4P12studied by optical conductivity

et al. 2012

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Optical conductivity [σ(ω)] of PrRu4P12 has been studied under high pressure to 14 GPa, at low temperatures to 8 K, and at photon energies 12 meV-1.1 eV. The energy gap in σ(ω) at ambient pressure, caused by a metal-insulator transition due to an unconventional charge-density-wave formation at 63 K, is gradually filled in with increasing pressure to 10 GPa. At 14 GPa and below 30 K, σ(ω) exhibits a pronounced Drude-type component due to free carriers. This indicates that the initial insulating ground state at zero pressure has been turned into a metallic one at 14 GPa. This is consistent with a previous resistivity study under pressure, where the resistivity rapidly decreased with cooling below 30 K at 14 GPa. The evolution of electronic structure with pressure is discussed in terms of the hybridization between the 4f and conduction electrons.

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Section: Methodsmentioning

confidence: 99%

Pressure suppression of unconventional charge-density-wave state in PrRu4P12studied by optical conductivity

et al. 2012

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“…To measure R(ω) under such a restricted condition, synchrotron radiation was used as high-brilliance infrared source 33 at the beam line BL43IR of SPring-8. 34 More technical details of the highpressure reflectance measurement have been described elsewhere. 32 Note that R d (ω) was measured at a sample/diamond interface, while R 0 (ω) was measured at a sample/vacuum interface.…”

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confidence: 99%

Pressure Suppression of Spin-Density-Wave Gap in the Optical Conductivity of SrFe₂As₂

et al. 2013

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Optical reflectance R(ω) of a pressure-induced superconductor SrFe2As2 has been measured under external pressure to 6 GPa and at temperatures to 8 K. Optical conductivity σ(ω) has been derived from the measured R(ω). At ambient pressure, in the antiferromagnetic state below TN=198 K, a pronounced feature develops in σ(ω) due to the opening of a spin density wave (SDW) gap, as already reported in the literature. With increasing pressure, the SDW gap feature in σ(ω) is progressively suppressed. At 4 GPa, where the sample is superconducting, the SDW gap feature in σ(ω) is strongly reduced than that at ambient pressure, but is still clearly observed. At 6 GPa, the SDW gap is completely suppressed. The pressure evolutions of the SDW gap magnitude and the spectral weight closely follow the pressure evolution of TN. PACS numbers:Regarding the superconductivity (SC) exhibited by Fe-based compounds, 1 the pressure-induced SC exhibited by the stoichiometric "122" compounds AFe 2 As 2 (A=Ba, Ca, Sr, Eu) have attracted much interest. 2-13 They exhibit SC with external pressure only, although many other families of Fe based superconductors require some form of chemical doping or deviation from stoichiometry to exhibit SC. 1 In particular, SrFe 2 As 2 (Sr122) and BaFe 2 As 2 (Ba122) show pressure-induced SC at relatively high temperatures of T c =34 K 5,7-9 and 28 K, 4,7,9,11 , respectively. Interestingly, the 122 compounds also show SC with chemical doping, as shown by (Sr, K)Fe 2 As 2 , 14 Sr(Fe,Co) 2 As 2 , 15 and SrFe 2 (As, P) 2 . 16 At ambient pressure, the stoichiometric 122 compounds are antiferromagnetic (AFM), poor metals. For Sr122 and Ba122, the AFM transition temperature (T N ) is 198 K and 136 K, respectively. At T N , the resistivity [ρ(T )] shows a kink and rapid decrease with cooling below T N . With increasing pressure, T N is gradually lowered, and the kink in ρ(T ) becomes broadened. Above a critical pressure, the SC appears. Similar suppression of AFM and emergence of SC have also been observed with chemical doping. [14][15][16] In this regard, both methods have provided a lot of insight, but one advantage of the pressure technique compared with chemical doping is that the former does not cause disorder in the crystal lattice.However, there is an additional complication regarding the pressure-induced SC in the 122 compounds. Namely, it has been shown that the pressure evolutions of the AFM and SC states strongly depend on the hydrostaticity. 8,11,12 Here, hydrostaticity refers to how isotropic the pressure acting on the sample is. The hydrostaticity in a high pressure experiment depends on the types of pressure cell and pressure transmitting medium used. Figure 1 summarizes the results of high pressure studies on Sr122. 4,5,7-9 As discussed in detail later, these results show that the AFM state is suppressed and SC appears at lower pressure when the applied pressure is less hydrostatic (more uniaxial). This may indicate that a uniaxial stress promotes SC in the 122 compounds.To probe the microscopic elect...

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“…2) [6,7]. Trace samples were picked up using a stereoscopic microscope, and pressed them between two diamond windows (Sumitomo Electric Hard metal Diamond Express) for making thin layer sample.…”

Section: Methodsmentioning

confidence: 99%

“…The schematic illustration of the optical path in the infrared microscope at Beamline BL43IR / SPring-8 [7]. The mirror SM1 and SM3 is a plane mirror.…”

Section: Figmentioning

confidence: 99%

The Study on Excavated Bast Fibers Using Synchrotron Polarized FT-IR Micro-Spectroscopy

2012

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Infrared microspectroscopy station at BL43IR of SPring-8

Cited by 44 publications

References 8 publications

Pressure suppression of unconventional charge-density-wave state in PrRu4P12studied by optical conductivity

Pressure suppression of unconventional charge-density-wave state in PrRu4P12studied by optical conductivity

Pressure Suppression of Spin-Density-Wave Gap in the Optical Conductivity of SrFe₂As₂

The Study on Excavated Bast Fibers Using Synchrotron Polarized FT-IR Micro-Spectroscopy

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Infrared microspectroscopy station at BL43IR of SPring-8

Cited by 44 publications

References 8 publications

Pressure suppression of unconventional charge-density-wave state in PrRu4P12studied by optical conductivity

Pressure suppression of unconventional charge-density-wave state in PrRu4P12studied by optical conductivity

Pressure Suppression of Spin-Density-Wave Gap in the Optical Conductivity of SrFe2As2

The Study on Excavated Bast Fibers Using Synchrotron Polarized FT-IR Micro-Spectroscopy

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Pressure Suppression of Spin-Density-Wave Gap in the Optical Conductivity of SrFe₂As₂