Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 14726-14733 |
| Number of pages | 8 |
| Journal | Dalton Transactions |
| Volume | 47 |
| Issue number | 41 |
| Early online date | 28 Sep 2018 |
| DOIs | |
| Publication status | Published - 7 Nov 2018 |
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The suppression of CMR in Nd(Mn1−xCox)AsO0.95F0.05. / Wildman, E. J.; McCombie, K. S.; Stenning, G. B. G.; McLaughlin, A. C. (Corresponding Author).
In: Dalton Transactions, Vol. 47, No. 41, 07.11.2018, p. 14726-14733.Research output: Contribution to journal › Article
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TY - JOUR
T1 - The suppression of CMR in Nd(Mn1−xCox)AsO0.95F0.05
AU - Wildman, E. J.
AU - McCombie, K. S.
AU - Stenning, G. B. G.
AU - McLaughlin, A. C.
N1 - This research is supported by the EPSRC (research grant EP/L002493/1). We also acknowledge the UK Science and Technology Facilities Council (STFC) for provision of beam time at ISIS.
PY - 2018/11/7
Y1 - 2018/11/7
N2 - The colossal magnetoresistance (CMR) observed in the oxypnictide NdMnAsO1−xFx has been further investigated. The magnetotransport is dominated by magnetopolarons. Magnetoresistance measurements of the series Nd(Mn1−xCox)AsO0.95F0.05 show that doping with cobalt on the manganese site pins the magnetopolarons and suppresses the CMR, which is completely destroyed by x = 0.047. The chemical doping results in non-stoichiometric samples, with both As and O vacancies. The relationship between the non-stoichiometry, magnetic order, electron doping and CMR is explored. The Nd antiferromagnetic transition and simultaneous reorientation of the Mn spins into the basal plane at 23 K (TSR) is not effected by Co doping. However, there is a significant decrease in TN(Mn) as the antiferromagnetic transition is suppressed from 360 K to 300 K as x increases from 0–0.047. The manganese moment at 10 K is also reduced from 3.86(2)μB to 3.21(2)μB over the same doping range. This reduction in the in-plane Mn moment decreases the electron–electron correlations below TSR and acts to further diminish the magnetoresistance.
AB - The colossal magnetoresistance (CMR) observed in the oxypnictide NdMnAsO1−xFx has been further investigated. The magnetotransport is dominated by magnetopolarons. Magnetoresistance measurements of the series Nd(Mn1−xCox)AsO0.95F0.05 show that doping with cobalt on the manganese site pins the magnetopolarons and suppresses the CMR, which is completely destroyed by x = 0.047. The chemical doping results in non-stoichiometric samples, with both As and O vacancies. The relationship between the non-stoichiometry, magnetic order, electron doping and CMR is explored. The Nd antiferromagnetic transition and simultaneous reorientation of the Mn spins into the basal plane at 23 K (TSR) is not effected by Co doping. However, there is a significant decrease in TN(Mn) as the antiferromagnetic transition is suppressed from 360 K to 300 K as x increases from 0–0.047. The manganese moment at 10 K is also reduced from 3.86(2)μB to 3.21(2)μB over the same doping range. This reduction in the in-plane Mn moment decreases the electron–electron correlations below TSR and acts to further diminish the magnetoresistance.
U2 - 10.1039/C8DT03071E
DO - 10.1039/C8DT03071E
M3 - Article
C2 - 30280742
VL - 47
SP - 14726
EP - 14733
JO - Dalton Transactions
JF - Dalton Transactions
SN - 1477-9226
IS - 41
ER -