Abstract
The effect of α-particle irradiation on a NdFeAs(O,F) thin film has been investigated to determine how the introduction of defects affects basic superconducting properties, including the critical temperature T c and the upper critical field H c2, and properties more of interest for applications, like the critical current density J c and the related pinning landscape. The irradiation-induced suppression of the film T c is significantly smaller than on a similarly damaged single crystal. Moreover H c2 behaves differently, depending on the field orientation: for H//c the H c2 slope monotonically increases with increasing disorder, whereas for H//ab it remains constant at low dose and it increases only when the sample is highly disordered. This suggests that a much higher damage level is necessary to drive the NdFeAs(O,F) thin film into the dirty limit. Despite the increase in the low temperature H c2, the effects on the J c(H//c) performances are moderate in the measured temperature and field ranges, with a shifting of the pinning force maximum from 4.5 to 6 T after an irradiation of 2 1015 cm-2. On the contrary, J c(H//ab) is always suppressed. The analysis demonstrates that irradiation does introduce point defects (PD) acting as pinning centres proportionally to the irradiation fluence but also suppresses the effectiveness of c-axis correlated pinning present in the pristine sample. We estimate that significant performance improvements may be possible at high field or at temperatures below 10 K. The suppression of the J c(H//ab) performance is not related to a decrease of the J c anisotropy as found in other superconductors. Instead it is due to the presence of PD that decrease the efficiency of the ab-plane intrinsic pinning typical of materials with a layered structure.
| Original language | English (US) |
|---|---|
| Article number | 034002 |
| Journal | Superconductor Science and Technology |
| Volume | 31 |
| Issue number | 3 |
| DOIs | |
| State | Published - Feb 5 2018 |
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Keywords
- critical current
- Fe-based superconductors
- irradiation, pinning properties
- NdFeAs(O,F)
ASJC Scopus subject areas
- Ceramics and Composites
- Condensed Matter Physics
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry
Cite this
Effect of α-particle irradiation on a NdFeAs(O,F) thin film. / Tarantini, C.; Iida, K.; Sumiya, N.; Chihara, M.; Hatano, T.; Ikuta, H.; Singh, Rakesh; Newman, Nathan; Larbalestier, D. C.
In: Superconductor Science and Technology, Vol. 31, No. 3, 034002, 05.02.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of α-particle irradiation on a NdFeAs(O,F) thin film
AU - Tarantini, C.
AU - Iida, K.
AU - Sumiya, N.
AU - Chihara, M.
AU - Hatano, T.
AU - Ikuta, H.
AU - Singh, Rakesh
AU - Newman, Nathan
AU - Larbalestier, D. C.
PY - 2018/2/5
Y1 - 2018/2/5
N2 - The effect of α-particle irradiation on a NdFeAs(O,F) thin film has been investigated to determine how the introduction of defects affects basic superconducting properties, including the critical temperature T c and the upper critical field H c2, and properties more of interest for applications, like the critical current density J c and the related pinning landscape. The irradiation-induced suppression of the film T c is significantly smaller than on a similarly damaged single crystal. Moreover H c2 behaves differently, depending on the field orientation: for H//c the H c2 slope monotonically increases with increasing disorder, whereas for H//ab it remains constant at low dose and it increases only when the sample is highly disordered. This suggests that a much higher damage level is necessary to drive the NdFeAs(O,F) thin film into the dirty limit. Despite the increase in the low temperature H c2, the effects on the J c(H//c) performances are moderate in the measured temperature and field ranges, with a shifting of the pinning force maximum from 4.5 to 6 T after an irradiation of 2 1015 cm-2. On the contrary, J c(H//ab) is always suppressed. The analysis demonstrates that irradiation does introduce point defects (PD) acting as pinning centres proportionally to the irradiation fluence but also suppresses the effectiveness of c-axis correlated pinning present in the pristine sample. We estimate that significant performance improvements may be possible at high field or at temperatures below 10 K. The suppression of the J c(H//ab) performance is not related to a decrease of the J c anisotropy as found in other superconductors. Instead it is due to the presence of PD that decrease the efficiency of the ab-plane intrinsic pinning typical of materials with a layered structure.
AB - The effect of α-particle irradiation on a NdFeAs(O,F) thin film has been investigated to determine how the introduction of defects affects basic superconducting properties, including the critical temperature T c and the upper critical field H c2, and properties more of interest for applications, like the critical current density J c and the related pinning landscape. The irradiation-induced suppression of the film T c is significantly smaller than on a similarly damaged single crystal. Moreover H c2 behaves differently, depending on the field orientation: for H//c the H c2 slope monotonically increases with increasing disorder, whereas for H//ab it remains constant at low dose and it increases only when the sample is highly disordered. This suggests that a much higher damage level is necessary to drive the NdFeAs(O,F) thin film into the dirty limit. Despite the increase in the low temperature H c2, the effects on the J c(H//c) performances are moderate in the measured temperature and field ranges, with a shifting of the pinning force maximum from 4.5 to 6 T after an irradiation of 2 1015 cm-2. On the contrary, J c(H//ab) is always suppressed. The analysis demonstrates that irradiation does introduce point defects (PD) acting as pinning centres proportionally to the irradiation fluence but also suppresses the effectiveness of c-axis correlated pinning present in the pristine sample. We estimate that significant performance improvements may be possible at high field or at temperatures below 10 K. The suppression of the J c(H//ab) performance is not related to a decrease of the J c anisotropy as found in other superconductors. Instead it is due to the presence of PD that decrease the efficiency of the ab-plane intrinsic pinning typical of materials with a layered structure.
KW - critical current
KW - Fe-based superconductors
KW - irradiation, pinning properties
KW - NdFeAs(O,F)
UR - http://www.scopus.com/inward/record.url?scp=85042531362&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85042531362&partnerID=8YFLogxK
U2 - 10.1088/1361-6668/aaa821
DO - 10.1088/1361-6668/aaa821
M3 - Article
AN - SCOPUS:85042531362
VL - 31
JO - Superconductor Science and Technology
JF - Superconductor Science and Technology
SN - 0953-2048
IS - 3
M1 - 034002
ER -