A compact and versatile dynamic flow cryostat for photon science

Linden, P. van der; Sala, M. Moretti; Henriquet, C.; Rossi, Mario E.; Ohgushi, Kenya; Fauth, François; Simonelli, Laura; Marini, Carlo; Fraga, Edmundo; Murray, Claire; Potter, Joseph L.; Krisch, M.

doi:10.1063/1.4966270

Cited by 20 publications

(10 citation statements)

References 22 publications

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“…Powder diffraction patterns were collected in the angular range 0-45° 2θ with a step size of 0.003°. Low temperatures were achieved using the lHe flow cryostat Dynaflow 21 and data were recorded at 220 K, 180K, 155K, 120 K and 10K.…”

Section: Introductionmentioning

confidence: 99%

Electronic and Magnetic Properties of Cation Ordered Sr₂Mn_2.23Cr_0.77As₂O₂

et al. 2020

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Several different mechanisms of magnetoresistance (MR) have been observed in 1111 LnMnAsO1-xFx oxypnictides (Ln = lanthanide) as a result of magnetic coupling between the Mn and Ln. Such phases also exhibit interesting magnetic phase transitions upon cooling. Sr2Mn2CrAs2O2 has been synthesised in order to investigate if it's possible to observe MR and/or magnetic phase transitions as a result of magnetic coupling between the Mn and Cr. Sr2Mn2CrAs2O2 crystallises with the I4/mmm tetragonal space group containing alternating MO2 2and M'2As2 2layers and neutron diffraction results demonstrate that the actual stoichiometry is Sr2Mn2.23Cr0.77As2O2. Cation order is present between Mn and Cr, with Cr predominantly occupying the square planar MO2 2site. Below 410 K the magnetic moments of the Mn/Cr ions in the M'2As2 2sublattice exhibit G-type antiferromagnetic order. The Mn/Cr moments within the MO2 2layer order below 167 K with a K2NiF4-typeantiferromagnetic structure which simultaneously induces a spin-flip of the magnetic moments in the M'2As2 2layers from a G-to C-type antiferromagnetic arrangement. The results demonstrate that the 2 superexchange interactions are finely balanced in Sr2Mn2.23Cr0.77As2O2. Sr2Mn2.23Cr0.77As2O2 is semiconducting and there is no evidence of MR. type antiferromagnetic arrangement. Electron doping of the M'2As2 2slabs is warranted to investigate this further. ASSOCIATED CONTENTSupporting Information. The supporting information includes Rietveld fits from neutron diffraction and synchrotron X-ray diffraction data and tables of crystallographic data.

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Section: Introductionmentioning

confidence: 99%

Electronic and Magnetic Properties of Cation Ordered Sr₂Mn_2.23Cr_0.77As₂O₂

et al. 2020

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“…The sample was enclosed in a glass capillary of 0.5 mm while data were registered on cooling at several temperatures between 295 and 10 K and on heating up to 400 K. Low temperatures were achieved using a liquid nitrogen cryostream (Oxford Cryosystems Series 700) and a so-called Dynaflow He flow cryostat. 59 The RT−HP XRD measurements were performed at the second end-station dedicated to HP measurements in diamond-anvil cells (DACs). The diffraction data were collected using a wavelength of 0.4246 Å (Sn Kedge) compressing the sample up to 23 GPa using a diamondanvil cell (DAC) with diamond culets of 400 μm diameter.…”

Section: Methodsmentioning

confidence: 99%

Crystal Structure, Lattice Dynamics, and Thermodynamic Properties of a Thermoelectric Orthorhombic BaCu₂Se₂ Compound

2020

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In the present work, we report a combined experimental and ab initio study of the crystal structure, lattice dynamics, and thermodynamic properties of a thermoelectric orthorhombic BaCu 2 Se 2 compound. The thermal and pressure evolution of the crystal structure is obtained using synchrotron X-ray diffraction (XRD) experiments. The lattice dynamics is studied through Raman scattering experiments and ab initio supercell calculations and reveals that the lowest Raman-active and infrared-active optical modes are at about 50 cm −1 (7 meV) and the presence of an optically silent low-energy optical mode at about 5 meV. From the determination of the heat capacity, the thermal expansion, and the bulk modulus, a Gruneisen parameter of about 2.03 is estimated. This rather large value, together with the presence of low-energy optical modes and the rather low Debye temperature in orthorhombic BaCu 2 Se 2 , can explain its low thermal conductivity. Additionally, we have also studied the lattice dynamics, the thermodynamic properties, and the stability of the metastable tetragonal BaCu 2 Se 2 against the stable orthorhombic phase and found that it might be stabilized at high temperature or high pressure.

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“…The spectra were normalized with the Athena and Artemis software, within the IFEFFIT package 29 . For the temperature control, we conditioned the sample in a cryostat 28,30,31 , cooling with a liquid nitrogen line (LN 2 -cryo) passed through the sample holder. The pressure was set to P ≈ 10 -3 mbar to maintain the X-ray beam intensity.…”

Section: X-ray Absorption Spectroscopymentioning

confidence: 99%