GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Anomalous behavior of the thermopower and temperature derivative of resistivity near the spin reorientation transition in Er2Fe14B : The 41st annual conference on magnetism and magnetic materials (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 5784-5786 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Experimental observation of the first-order nature of the spin reorientation transition in polycrystalline Er2Fe14B through high resolution resistivity, thermopower and 57Fe Mössbauer data is reported. Both a steplike decrease in resistivity and an increase in thermopower over a very narrow temperature interval around 323 K indicate a discontinuous spin reorientation transition. This is consistent with the change in sign of the quadrupolar shifts at all Fe sites at this temperature, derived from the Mössbauer spectra, which are indicative for the transition from planar to uniaxial anisotropy with increasing temperature. The symmetrical lineshape of the sharp singularity recorded in the temperature derivative of resistivity provides unambiguous evidence for the first-order nature of the spin reorientation. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.364667
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Oxidation state and superconducting properties of Y1−xPrxSr2Cu2.85Re0.15O7+δ (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 6884-6887 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Superconductivity exists in orthorhombic Y1−xPrxSr2Cu2.85Re0.15O7+δ up to a critical concentration (xcr) of 0.65. A progressive decrease in Tc occurs as x increases from 0 to 0.65. A further increase in x leads to a tetragonal transformation and as a consequence the Tc vanishes; however, the orthorhombicity of these Sr-based compounds is much lower than that observed for the Ba analog, Y1−xPrxBa2Cu3O7−δ and, hence, the Tc. On the one hand, crystal chemistry correlations indicate that the Pr ion is in trivalent state while on the other hand, the stabilizing cation, viz., Re, is in hexavalent state which accounts for the excess oxygen (〉7.0) in the system. The high xcr value of the Sr series compared to the Ba series (xcr=0.55) is attributed to the much reduced orbital overlap of the trivalent Pr(4f ) state with the Cu(3dx2−y2)–O(2p) conduction band, via hole localization and/or pair breaking, and is not due to the much discussed hole filling by tetravalent Pr. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.363758
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Microstructural study of yttria stabilized zirconia buffered sapphire for YBa2Cu3O7−δ thin films (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 940-946 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Yttria stabilized zirconia (YSZ) buffer layers were grown by rf-magnetron sputtering on the r (11¯02) plane of sapphire for YBa2Cu3O7−δ (YBCO) thin film deposition. Microstructural changes of YSZ buffer layers grown using different sputtering conditions (5, 10, and 20 mTorr; Ar/O2 gas mix ratio of 9:1 and 1:1) were monitored by atomic force microscopy (AFM). Films grown using a lower oxygen partial pressure (5 mTorr) and a higher Ar/O2 ratio (9:1) showed smooth surface morphology and the average surface roughness increased with an increase in oxygen partial pressure. YBCO films in situ grown by pulsed laser deposition on sapphire with a YSZ buffer layer deposited using optimized sputtering parameters (5 mTorr gas pressure, 9:1 Ar/O2 ratio) yielded the highest critical density, Jc≈4.5×106 A cm−2 at 77 K. An excellent correlation between microstructure and Jc has been found and AFM has proved to be important for the study of the microstructure of films. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360876
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Pulsed laser ablation: A new route to synthesize novel superconducting compounds as oriented films (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 1082-1091 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report here the significance of the pulsed laser ablation technique in stabilizing strained lattices that do not form by the conventional ceramic method and show that the technique offers unique possibilities to probe the structure property relationship in complicated systems. One of such systems is LuBa2Cu3O7−δ; a systematic investigation of structural (in)stability of its superconducting phase is presented here. Our analysis suggests that the system suffers from internal strain due to lower ionic radius of Lu3+; however, the structure can be stabilized only as oriented films on 〈100〉 LaAlO3, 〈100〉 SrTiO3, and 〈100〉 MgO, with excellent superconducting properties (Jc≈5.0×106 A cm−2 at 77 K). We have also investigated similar compounds having their stability close to their crystallographic limit. The important feature of these metastable phases is that they grow only as oriented films. Free energy of epitaxial growth of strained films are investigated and a simple growth model is proposed based on our observation. Importance of this growth model in explaining the superconductor–normal-metal–superconductor type of junctions, observed in high-Tc superconductors is highlighted. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360898
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Optical spectroscopy study of the role of Ag in laser ablated YBa2Cu3O7−δ thin films (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 5204-5205 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have found evidence through optical spectroscopy that AgO is indeed generated in the laser plume during pulsed laser deposition of YBa2Cu3O7−δ (YBCO) thin films using Ag-doped YBCO targets. This supports our earlier conjecture that formation of AgO in the plume and its subsequent dissociation at the elevated substrate temperature (since AgO is unstable above 350 °C) provides active oxygen to the YBCO lattice, thereby increasing oxygen incorporation during growth of YBCO thin films. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359694
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Surface resistance and residual losses of Ag-doped YBa2Cu3O7−δ thin films on sapphire (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 4116-4118 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: High-quality Ag-doped YBa2Cu3O7−δ thin films have been grown by laser ablation on R-plane 〈11¯02〉 sapphire without any buffer layer. Thin films have been found to be highly c-axis oriented with Tc=90 K, transition width ΔT≤1 K, and transport Jc=1.2×106 A cm−2 at 77 K in self-field conditions. The microwave surface resistance of these films measured on patterned microstrip resonators has been found to be 530 μΩ at 10 GHz at 77 K which is the lowest reported on unbuffered sapphire. Improved in-plane epitaxy and reduced reaction rate between the substrate and the film caused due to Ag in the film are believed to be responsible for this greatly improved microwave surface resistance. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359496
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Silver doping and its influence on the oxygenation during in situ growth of YBa2Cu3O7−x thin films (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 1349-1351 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The influence of Ag doping on both oxygenation and deoxygenation during growth of YBa2Cu3O7−x films at 700 °C by pulsed laser deposition has been studied. Experiments show that undoped and Ag-doped films grown at 200 mTorr oxygen pressure and quenched immediately after termination of growth have a superconducting transition temperature Tc of 61 and 86 K, respectively. The high Tc of 86 K obtained with quenched Ag-doped films is thought to be due to both enhanced oxygen incorporation and reduced deoxygenation associated with Ag doping. These results show that Ag-doped YBa2Cu3O7−x films could be crucial for realizing devices based on multilayer structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357802
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Temperature dependence of the electrical resistivity and thermopower of U2Ni2In and Nd2Ni2Sn : The 40th annual conference on magnetism and magnetic materials (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 6355-6357 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Accurate measurements of the electrical resistivity (ρ,dρ/dT) and of the thermoelectric power (S,dS/dT) were performed in the ternary compounds U2Ni2In and Nd2Ni2Sn from 4 K to 250 K, and the results are compared with those previously obtained in U2Ni2Sn. The pair U2Ni2In/U2Ni2Sn enables us to study the influence of the p-electron character (and other band effects related to the elements In/Sn) on the transport properties, whereas the pair Nd2Ni2Sn/U2Ni2Sn provides direct information on the role played by the 4f/5f electrons. All these compounds order initially in the antiferromagnetic state, exhibiting a characteristic minimum in dρ/dT at TN. In the U2Ni2In compound a drastic reduction is observed in ρ(T) slightly below TN, suggesting the coexistence of the antiferromagnetic state with a coherent Kondo effect when T≤0.8 TN. In Nd2Ni2Sn we observe two distinct phase transitions below TN, of first-order character and likely associated with order-order magnetic transitions. The anomalous behavior of ρ(T) in the paramagnetic phase of the Nd2Ni2Sn compound can be satisfactorily described in terms of crystal field effects associated with the 4f-electron levels. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.361998
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Two-dimensional growth model for laser-ablated Ag-doped YBa2Cu3O7−x thin films (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 5802-5808 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ag-doped YBa2Cu3O7−x (YBCO) thin films using 2–20 wt % Ag-doped YBCO targets have been grown in situ by the laser ablation technique. The improvement in properties in normal and superconducting states of Ag-doped YBCO films has been interpreted using a two-dimensional growth model. The model is simple and is based on widely accepted characteristics of Ag such as its flux action at high temperatures and its nonreactivity with YBCO phase. Experimental evidence in support of the growth model is presented by carrying out microstructural studies and measurements of room-temperature resistivity, critical current density, and microwave surface resistance in superconducting state. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359159
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Surface resistance, residual losses, and granularity in Ag-doped YBa2Cu3O7−δ thin films (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 4258-4260 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have studied microwave surface resistance Rs and residual resistance Rres in undoped and Ag-doped laser ablated thin-film YBa2Cu3O7−δ microstrip resonators on LaAlO3 substrates. While the undoped films showed a frequency dependence Rs∝fp, where p=1.9±1, Ag-doped films showed p=1.6±1 and 1.4±1 for 5 and 10 wt % Ag doping, respectively. Lower p values and higher Rres observed in Ag-doped films indicate a metallic contribution. However, the advantage of Ag-doped films has been shown to be at 77 K at which they not only have a lower Rs but also a low dRs/dT, thus making them superior to undoped films for microwave devices operating at 77 K.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.355965
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...