TY - JOUR
T1 - Impurity effects on the electronic state in the undoped (Ce-free) superconductor T¤-La1.8Eu0.2CuO4 studied by muon spin relaxation
AU - Kawamata, Takayuki
AU - Ohashi, Koki
AU - Takamatsu, Tomohisa
AU - Adachi, Tadashi
AU - Kato, Masatsune
AU - Watanabe, Isao
AU - Koike, Yoji
N1 - Funding Information:
Acknowledgments This work was supported by JSPS KAKENHI Grant Number 17H02915.
Publisher Copyright:
© 2018 The Physical Society of Japan.
PY - 2018
Y1 - 2018
N2 - To investigate the electronic state in the undoped (Ce-free) superconductor TA-La1.8Eu0.2CuO4 (TA-LECO), we have performed muon spin relaxation measurements using impurity-substituted superconducting (SC) reduced samples of TA-La1.8Eu0.2Cu1−yMyO4 (M = Ni, Zn; y ¼ 0; 0:005; 0:01) and also a non-SC as-grown sample of TA-LECO. It has been found that phase separation into SC and magnetically ordered regions takes place and that no magnetic order is developed around M in the SC regions of the M-substituted reduced samples. The magnetic transition temperature in the magnetically ordered regions has been found to increase and decrease with the Ni and Zn substitutions, respectively. Accordingly, it has been concluded that the electronic state in the SC regions of TA-LECO is similar to that in overdoped T-La2−xSrxCuO4 and understood as a strongly correlated itinerant electron system, while the magnetically ordered regions are due to localized Cu spins. The role of the reduction annealing in the appearance of superconductivity in TA-cuprates has been discussed.
AB - To investigate the electronic state in the undoped (Ce-free) superconductor TA-La1.8Eu0.2CuO4 (TA-LECO), we have performed muon spin relaxation measurements using impurity-substituted superconducting (SC) reduced samples of TA-La1.8Eu0.2Cu1−yMyO4 (M = Ni, Zn; y ¼ 0; 0:005; 0:01) and also a non-SC as-grown sample of TA-LECO. It has been found that phase separation into SC and magnetically ordered regions takes place and that no magnetic order is developed around M in the SC regions of the M-substituted reduced samples. The magnetic transition temperature in the magnetically ordered regions has been found to increase and decrease with the Ni and Zn substitutions, respectively. Accordingly, it has been concluded that the electronic state in the SC regions of TA-LECO is similar to that in overdoped T-La2−xSrxCuO4 and understood as a strongly correlated itinerant electron system, while the magnetically ordered regions are due to localized Cu spins. The role of the reduction annealing in the appearance of superconductivity in TA-cuprates has been discussed.
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U2 - 10.7566/JPSJ.87.094717
DO - 10.7566/JPSJ.87.094717
M3 - Article
AN - SCOPUS:85052935129
VL - 87
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 9
M1 - 094717
ER -