Abstract
Vortex excitations and creep regimes in YBa2Cu3O 7 (YBCO) films with nonsuperconducting nanorods (columnar defects) and/or nanoparticles in a low external magnetic field H oriented perpendicular to the film surface have been identified using standard DC magnetization relaxation measurements. It was found that by increasing the pinning energy dispersion through nanoparticle addition the relevant changes in the temperature T variation of the normalized magnetization relaxation rate S appear at relatively high temperatures (T ∼ 65 K for H = 2 kOe), owing to the inhibition of double vortex-kink formation. This indicates that the often observed S(T) maximum at low T (around 30 K) is not related to the excitation of double vortex kinks and super-kinks in specimens with columnar defects, as previously believed. The low-T S(T) maximum is present in the case of strongly pinned specimens without nanorods, as well, and depends on the film thickness, which definitely shows that it is caused by thermo-magnetic instabilities, as recently suggested.
| Original language | English |
|---|---|
| Pages (from-to) | 40-43 |
| Number of pages | 4 |
| Journal | Physica C: Superconductivity and its Applications |
| Volume | 500 |
| DOIs | |
| Publication status | Published - 2014 May 15 |
| Externally published | Yes |
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Keywords
- Magnetization relaxation
- Nonsuperconducting nanorods and nanoparticles
- Vortex excitations and creep regimes
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering
Cite this
Evolution of vortex dynamics in YBa2Cu3O7 films with nanorods by adding nanoparticles. / Miu, L.; Mele, Paolo; Crisan, A.; Ionescu, A.; Miu, D.
In: Physica C: Superconductivity and its Applications, Vol. 500, 15.05.2014, p. 40-43.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evolution of vortex dynamics in YBa2Cu3O7 films with nanorods by adding nanoparticles
AU - Miu, L.
AU - Mele, Paolo
AU - Crisan, A.
AU - Ionescu, A.
AU - Miu, D.
PY - 2014/5/15
Y1 - 2014/5/15
N2 - Vortex excitations and creep regimes in YBa2Cu3O 7 (YBCO) films with nonsuperconducting nanorods (columnar defects) and/or nanoparticles in a low external magnetic field H oriented perpendicular to the film surface have been identified using standard DC magnetization relaxation measurements. It was found that by increasing the pinning energy dispersion through nanoparticle addition the relevant changes in the temperature T variation of the normalized magnetization relaxation rate S appear at relatively high temperatures (T ∼ 65 K for H = 2 kOe), owing to the inhibition of double vortex-kink formation. This indicates that the often observed S(T) maximum at low T (around 30 K) is not related to the excitation of double vortex kinks and super-kinks in specimens with columnar defects, as previously believed. The low-T S(T) maximum is present in the case of strongly pinned specimens without nanorods, as well, and depends on the film thickness, which definitely shows that it is caused by thermo-magnetic instabilities, as recently suggested.
AB - Vortex excitations and creep regimes in YBa2Cu3O 7 (YBCO) films with nonsuperconducting nanorods (columnar defects) and/or nanoparticles in a low external magnetic field H oriented perpendicular to the film surface have been identified using standard DC magnetization relaxation measurements. It was found that by increasing the pinning energy dispersion through nanoparticle addition the relevant changes in the temperature T variation of the normalized magnetization relaxation rate S appear at relatively high temperatures (T ∼ 65 K for H = 2 kOe), owing to the inhibition of double vortex-kink formation. This indicates that the often observed S(T) maximum at low T (around 30 K) is not related to the excitation of double vortex kinks and super-kinks in specimens with columnar defects, as previously believed. The low-T S(T) maximum is present in the case of strongly pinned specimens without nanorods, as well, and depends on the film thickness, which definitely shows that it is caused by thermo-magnetic instabilities, as recently suggested.
KW - Magnetization relaxation
KW - Nonsuperconducting nanorods and nanoparticles
KW - Vortex excitations and creep regimes
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U2 - 10.1016/j.physc.2014.03.002
DO - 10.1016/j.physc.2014.03.002
M3 - Article
VL - 500
SP - 40
EP - 43
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
ER -