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Showing 1 to 16 of 16 for “"iron based superconductors"”.
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Orbital order in iron-based superconductors
… structural and the magnetic transitions in the iron-based superconductors. We will discuss this orbital order in the framework of the local-itinerant dichotomy. First, due to the spatial anisotropy of the occupied orbitals that form the local moments, the magnetic exchange constants acquire …
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Point contact spectroscopy studies of the iron based superconductors
… the normal and superconducting phases of the iron based superconductors. It is shown that apart from probing superconductors by Andreev reflection, PCS is also a useful technique to study exotic electron matter in correlated materials. The point contact junctions are made by two separate …
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Probing nano-scale atomic and electronic structures of iron-based superconductors
The discovery of iron-based high-Tc superconductors has attracted renewed interests in unconventional superconductivity after the intense research in the past two decades on cuprates. Similar to the cuprate superconductors, the iron-based superconductors exhibit high Tc that the …
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Probing the superconducting order parameter of Iron-based superconductors through the Josephson effect
We report the results we obtained regarding the use of the Josephson effect to probe the symmetry of the superconducting order parameter of Co-doped Ba(FeAs)2 crystals (Ba122). This measurements were carried out to test the validity of the s± model, which predicts the pairing in the multiband Ba122 …
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Pairing symmetry, competing orders, and quantum criticality in iron based superconductors via London penetration depth measurements
The temperature dependence of the magnetic penetration depth (λ) has been measured in single crystals of BaFe2As2 that have been driven into superconductivity by several different kinds of dopants, specifically potassium, cobalt, and phosphorous. In (Ba{0.6}K{0.4})Fe2As2 the low temperature …
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Point-contact Andreev reflection studies on superconductors
… on PCARS as applied to various unconventional superconductors, such as NbSe$_2$, the borocarbide family RNi$_2$B$_2$C (R=Lu, Y) and the recently-discovered, iron-based superconductors AFe$_2$As$_2$ (A=Ba, Sr) with both hole and electron doping. The superconducting gap distribution observed from …
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Transport and thermodynamic studies of the superconductors A3T4Sn13 and YFe2Ge2
… $T$ = Ir, Rh) is a family of quasi-skutterudite superconductors with moderate $T_c$’s between 4 and 8 K. Although the superconductivity is believed to be phonon-mediated with s-wave pairing symmetry, an unusual second-order structural transition makes this material family fascinating to study. …
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Fluxon Dynamics In Two-Gap Superconductor-Based Long Josephson Junction
<p>A superconducting tunnel junction with two-gap superconductors, such as MgB<sub>2</sub> and iron-based superconductors, can lead to more interesting phase dynamics than those with one-gap superconductors. The phase dynamics in a long Josephson junction (LJJ) may be described by using the …
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High Pressure Studies of Superconductivity
… to enhance the properties of existing superconductors, to find new superconductors, and to test the validity of theoretical models. This thesis presents a series of high pressure measurements performed in both He-gas and diamond anvil cell systems on various superconductors and on …
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A study of three transition metal compounds and their applications
… FeSe_{1-x} is one of the newly discovered iron-based superconductors. As a binary transition metal compound, it is of great research interest due to the simple stacking 2d-layered structure. The itinerant or localized nature of the electrons in Fe^{2+} ion has been debated but not …
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Unconventional Superconductivity in the Layered Iron Germanide YFe2Ge2
… of superconductivity in LaFePO, numerous iron-based superconductors have been identified within diverse structure families. Superconductivity in the layered iron germanide YFe$_2$Ge$_2$ was first reported in 2014. It stands out from the commonly known iron- based superconductor families …
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Thermal expansion and magnetostriction studies on iron pnictides
… and magnetostriction of novel superconducting iron pinictides and related materials. In particular, \re~with R\,=\,La, Ce, Pr, Sm, Gd, \laf~and Ca(Fe$_{1-x}$Co$_x$)$_2$As$_2$ have been investigated. The data on polycrystalline \laf~are the first published thermal expansion data on this …
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Superconductivity in oxygen doped iron telluride by molecular beam epitaxy
Iron base superconductor have gained much attention in the research community. They offer great potentials to improve our understanding of the subject of superconductivity by having another family of high temperature superconductors to compare and contrast to the cuprates. Practically, the iron …
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Synthesis and Properties of New Oxychalcogenide Materials
… they are close relatives of the LaOFeAs superconductors. Chapter 2 describes the synthetic and analytical techniques used in this project. The theory behind the powder diffraction techniques used throughout is described, and information on specific methodology used in the data collections …
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Correlated low temperature states of YFe2Ge2 and pressure metallised NiS2
… rare case of a non-pnictide and non-chalcogenide iron based superconductor with the 1-2-2 structure. This thesis describes growth and study of a new generation of high quality YFe$_{2}$Ge$_{2}$ samples with residual resistance ratios reaching 200. Measurements of resistivity, heat capacity and …