scholarly journals A Comparison of Methods for Computing the Residual Resistivity Ratio of High-Purity Niobium

2011 ◽  
Vol 116 (1) ◽  
pp. 489 ◽  
Author(s):  
J. D. Splett ◽  
D. F. Vecchia ◽  
L.F. Goodrich
Keyword(s):  
High Purity ◽  
Residual Resistivity ◽  
Comparison Of Methods ◽  
Residual Resistivity Ratio ◽  
Resistivity Ratio

Einfluß des Präparationsverfahrens auf das Restwiderstandsverhältnis kleiner Niobkugeln/ The Influence of Preparation on the Residual Resistivity Ratio of Small Spherical Niobium Samples

1978 ◽  
Vol 33 (10) ◽  
pp. 1158-1160 ◽  
Author(s):  
K. Gärtner ◽  
M. Westphal
Keyword(s):  
Heat Treatment ◽  
High Purity ◽  
Residual Resistivity ◽  
Temperature Gradients ◽  
Residual Resistivity Ratio ◽  
Resistivity Ratio ◽  
Influence Of Temperature ◽  
Tunneling Junctions

Abstract A technique for preparing spherical niobium samples of high purity is described. The preparation of tunneling junctions starts from such spheres. The influence of temperature gradients during a heat treatment on the sample purity is discussed.

scholarly journals Precise Purity-Evaluation of High-Purity Copper by Residual Resistivity Ratio

1997 ◽  
Vol 38 (8) ◽  
pp. 714-718 ◽  
Author(s):  
Kouji Mimura ◽  
Yukio Ishikawa ◽  
Minoru Isshiki ◽  
Masanori Kato
Keyword(s):  
High Purity ◽  
Residual Resistivity ◽  
Residual Resistivity Ratio ◽  
Resistivity Ratio ◽  
Purity Evaluation ◽  
Purity Copper

scholarly journals Proximity effect in [Nb(1.5 nm)/Fe(x)]10/Nb(50 nm) superconductor/ferromagnet heterostructures

2020 ◽  
Vol 11 ◽  
pp. 1254-1263
Author(s):  
Yury Khaydukov ◽  
Sabine Pütter ◽  
Laura Guasco ◽  
Roman Morari ◽  
Gideok Kim ◽  
...  
Keyword(s):  
Intermediate State ◽  
Proximity Effect ◽  
Intermediate Phase ◽  
Ferromagnetic Layer ◽  
Residual Resistivity ◽  
Neutron Reflectometry ◽  
Superconducting Transition ◽  
Residual Resistivity Ratio ◽  
Resistivity Ratio ◽  
Weak Ferromagnetic

We have investigated the structural, magnetic and superconduction properties of [Nb(1.5 nm)/Fe(x)]10 superlattices deposited on a thick Nb(50 nm) layer. Our investigation showed that the Nb(50 nm) layer grows epitaxially at 800 °C on the Al2O3(1−102) substrate. Samples grown at this condition possess a high residual resistivity ratio of 15–20. By using neutron reflectometry we show that Fe/Nb superlattices with x < 4 nm form a depth-modulated FeNb alloy with concentration of iron varying between 60% and 90%. This alloy has weak ferromagnetic properties. The proximity of this weak ferromagnetic layer to a thick superconductor leads to an intermediate phase that is characterized by a suppressed but still finite resistance of structure in a temperature interval of about 1 K below the superconducting transition of thick Nb. By increasing the thickness of the Fe layer to x = 4 nm the intermediate phase disappears. We attribute the intermediate state to proximity induced non-homogeneous superconductivity in the structure.

Origin of Diversified Transport Properties of MgB2

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3672-3674
Author(s):  
Kijoon H. P. Kim ◽  
C. U. Jung ◽  
Heon-Jung Kim ◽  
Min-Seok Park ◽  
Mun-Seog Kim ◽  
...  
Keyword(s):  
Low Temperature ◽  
Transport Properties ◽  
Temperature Region ◽  
Residual Resistivity ◽  
Transition Width ◽  
Residual Resistivity Ratio ◽  
Resistivity Ratio ◽  
Excess Mg

We investigated the transport properties of MgB 2 while changing the contents of excess Mg. The samples containing almost no excess Mg showed the highest Tc and the sharpest transition width (ΔTc). A residual resistivity ratio (RRR) of ~ 5.8, and a magnetoresistance (MR) of 12%, at 40 K, were obtained for this stoichiometric sample. Moreover, no upturn of resistivity in a low temperature region at 10 Tesla was observed. However, the samples containing appreciable amounts of excess Mg showed quite different behaviors; the values of ΔTc, RRR and MR were much larger. Surprisingly, big upturn appeared in this Mg-excess MgB 2

scholarly journals High-sensitivity of initial SrO growth on the residual resistivity in epitaxial thin films of SrRuO$$_3$$ on SrTiO$$_3$$ (001)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Uddipta Kar ◽  
Akhilesh Kr. Singh ◽  
Song Yang ◽  
Chun-Yen Lin ◽  
Bipul Das ◽  
...  
Keyword(s):  
Volume Fraction ◽  
High Sensitivity ◽  
Orthorhombic Phase ◽  
Residual Resistivity ◽  
Epitaxial Thin Films ◽  
Residual Resistivity Ratio ◽  
Resistivity Ratio ◽  
Growth Technique ◽  
X Ray ◽  
High Crystallinity

AbstractThe growth of SrRuO$$_3$$ 3 (SRO) thin film with high-crystallinity and low residual resistivity (RR) is essential to explore its intrinsic properties. Here, utilizing the adsorption-controlled growth technique, the growth condition of initial SrO layer on TiO$$_2$$ 2 -terminated SrTiO$$_3$$ 3 (STO) (001) substrate was found to be crucial for achieving a low RR in the resulting SRO film grown afterward. The optimized initial SrO layer shows a c(2 $$\times $$ × 2) superstructure that was characterized by electron diffraction, and a series of SRO films with different thicknesses (ts) were then grown. The resulting SRO films exhibit excellent crystallinity with orthorhombic-phase down to $$t \approx $$ t ≈ 4.3 nm, which was confirmed by high resolution X-ray measurements. From X-ray azimuthal scan across SRO orthorhombic (02 ± 1) reflections, we uncover four structural domains with a dominant domain of orthorhombic SRO [001] along cubic STO [010] direction. The dominant domain population depends on t, STO miscut angle ($$\alpha $$ α ), and miscut direction ($$\beta $$ β ), giving a volume fraction of about 92 $$\%$$ % for $$t \approx $$ t ≈ 26.6 nm and $$(\alpha , \beta ) \approx $$ ( α , β ) ≈ (0.14$$^{\mathrm{o}}$$ o , 5$$^{\mathrm{o}}$$ o ). On the other hand, metallic and ferromagnetic properties were well preserved down to t$$\approx $$ ≈ 1.2 nm. Residual resistivity ratio (RRR = $$\rho ({\mathrm{300 K}})$$ ρ ( 300 K ) /$$\rho ({\mathrm{5K}})$$ ρ ( 5 K ) ) reduces from 77.1 for t$$\approx $$ ≈ 28.5 nm to 2.5 for t$$\approx $$ ≈ 1.2 nm, while $$\rho ({\mathrm{5K}})$$ ρ ( 5 K ) increases from 2.5 $$\upmu \Omega $$ μ Ω cm for t$$\approx $$ ≈ 28.5 nm to 131.0 $$\upmu \Omega $$ μ Ω cm for t$$\approx $$ ≈ 1.2 nm. The ferromagnetic onset temperature ($$T'_{\mathrm{c}}$$ T c ′ ) of around 151 K remains nearly unchanged down to t$$\approx $$ ≈ 9.0 nm and decreases to 90 K for t$$\approx $$ ≈ 1.2 nm. Our finding thus provides a practical guideline to achieve high crystallinity and low RR in ultra-thin SRO films by simply adjusting the growth of initial SrO layer.

Mechanical, Thermal and Electrical Characteristics of Conventionally Cast and Cold-Rolled 5754-Sc-Zr Aluminium Alloy

2019 ◽  
Vol 22 ◽  
pp. 55-64
Author(s):  
Martin Vlach ◽  
Veronika Kodetová ◽  
Hana Kudrnová ◽  
Michal Leibner ◽  
Marián Vlček ◽  
...  
Keyword(s):  
Cold Rolling ◽  
Electron Backscatter Diffraction ◽  
Residual Resistivity ◽  
Precipitation Process ◽  
Residual Resistivity Ratio ◽  
Scanning Calorimetry ◽  
Resistivity Ratio ◽  
Cold Rolled ◽  
Initial Difference ◽  
C 30

The effect of cold-rolling on mechanical, thermal, and electrical properties as well as microstructure behaviour of the Al-2.93wt.%Mg-0.34wt.%Mn-0.33wt.%Si-0.22wt.%Fe-0.19wt.%Cr-0.24wt.%Sc-0.06wt.%Zr was studied. The material was investigated during step-by-step isochronal annealing in a temperature range from room temperature up to 540 °C and during isothermal annealing at 200, 450 and 550 °C. Precipitation reactions were studied by electrical resistometry, conductivity, (micro) hardness measurements and differential scanning calorimetry. The hardening effect appears due to the additional precipitation of the Al3Sc and/or Al3(Sc,Zr) particles. The distinct changes in residual resistivity ratio above ~ 330 °C are probably caused by precipitation of the Mn (,Fe,Cr)-containing particles. This precipitation process is highly influenced by cold rolling but it has a negligible effect on hardness. The apparent activation energy values for additional formation of the Al3Sc and/or Al3(Sc,Zr) particles were determined. The kinetics of the Al3(Sc,Zr)-phase precipitation seems to be independent of Mn-and Mg-addition in the studied alloys. A partial recrystallization of the cold-rolled alloy was registered by electron backscatter diffraction after annealing at 550 °C. The initial difference in microhardness introduced by cold rolling is almost removed after annealing at 550 °C/30 min.

scholarly journals Variation of transition temperatures and residual resistivity ratio in vapor-grown FeSe

2016 ◽  
Vol 94 (2) ◽  
Author(s):  
A. E. Böhmer ◽  
V. Taufour ◽  
W. E. Straszheim ◽  
T. Wolf ◽  
P. C. Canfield
Keyword(s):  
Residual Resistivity ◽  
Transition Temperatures ◽  
Residual Resistivity Ratio ◽  
Resistivity Ratio
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