| 1. |
- Stilp, E., et al.
(författare)
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Magnetic phase diagram of low-doped La2-xSrxCuO4 thin films studied by low-energy muon-spin rotation
- 2013
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 88:6, s. 064419-1-064419-11
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Tidskriftsartikel (refereegranskat)abstract
- The magnetic phase diagram of La2-xSrxCuO4 thin films grown on single-crystal LaSrAlO4 substrates has been determined by low-energy muon-spin rotation. The diagram shows the same features as the one of bulk La2-xSrxCuO4, but the transition temperatures between distinct magnetic states are significantly different. In the antiferromagnetic phase the Neel temperature T-N is strongly reduced, and no hole spin freezing is observed at low temperatures. In the disordered magnetic phase (x greater than or similar to 0.02) the transition temperature to the cluster spin-glass state T-g is enhanced. Possible reasons for the pronounced differences between the magnetic phase diagrams of thin-film and bulk samples are discussed.
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| 2. |
- Wojek, Bastian M., et al.
(författare)
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Magnetism, superconductivity, and coupling in cuprate heterostructures probed by low-energy muon-spin rotation
- 2012
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 85:2, s. 024505-
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Tidskriftsartikel (refereegranskat)abstract
- We present a low-energy muon-spin-rotation study of the magnetic and superconducting properties of YBa(2)Cu(3)O(7-delta)/PrBa(2)Cu(3)O(7-delta) trilayer and bilayer heterostructures. By determining the magnetic-field profiles throughout these structures, we show that a finite superfluid density can be induced in otherwise semiconducting PrBa(2)Cu(3)O(7-delta) layers when juxtaposed to YBa(2)Cu(3)O(7-delta) "electrodes," while the intrinsic antiferromagnetic order is unaffected.
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| 3. |
- Kozhevnikov, V., et al.
(författare)
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Nonlocal effect and dimensions of Cooper pairs measured by low-energy muons and polarized neutrons in type-I superconductors
- 2013
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Ingår i: Physical Review B Condensed Matter. - : American Physical Society. - 0163-1829 .- 1095-3795. ; 87:10, s. 104508-
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Tidskriftsartikel (refereegranskat)abstract
- The Pippard coherence length xi(0) (the size of a Cooper pair) in two extreme type-I superconductors (In and Sn) was determined directly through high-resolution measurement of the nonlocal electrodynamic effect combining low-energy muon spin rotation spectroscopy and polarized neutron reflectometry. The renormalization factor Z = m*(cp)/2m (m*(cp) and m are the mass of the Cooper pair and the electron, respectively) resulting from the electron-phonon interaction, and the temperature-dependent London penetration depth lambda(L)(T) were determined as well. An expression linking xi(0), Z, and lambda(L)(0) is introduced and experimentally verified. This expression allows one to determine experimentally the Pippard coherence length in any superconductor, independent of whether the superconductor is local or nonlocal, conventional or unconventional.
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| 4. |
- Ofer, O., et al.
(författare)
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Absolute value and temperature dependence of the magnetic penetration depth in Ba(Co 0.074Fe 0.926) 2As 2
- 2012
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 85:6, s. 060506-
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Tidskriftsartikel (refereegranskat)abstract
- The absolute value and temperature dependence of the in-plane magnetic penetration depth lambda have been measured on a single crystal of Ba(Co0.074Fe0.926)(2)As-2 using low-energy muon-spin rotation and microwave cavity perturbation. The magnetic field profiles in the Meissner state are consistent with a local London model beyond a depth of 15 nm. We determine the gap symmetry through measurements of the temperature dependence of the superfluid density which follows a two-gap s-wave model over the entire temperature range below T-c. While the intermediate to high temperature data is well fit by an energy gap model in the BCS-like (weak-coupling) limit, a second smaller gap becomes apparent at low temperatures.
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