Electron-Doping Effect on Tc in the Undoped (Ce-Free) Superconductor T′-La1.8Eu0.2CuO4 Studied by the Fluorine Substitution for Oxygen

Sunohara, Toshiki; Shiosaka, Kota; Takamatsu, Tomohisa; Noji, Takashi; Kato, Masaru; Koike, Yasuhiro

doi:10.7566/jpsj.89.014701

Cited by 8 publications

(3 citation statements)

References 27 publications

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“…This result is different from the phase diagram of La 2−x Sr x CuO 4 (LSCO), where the optimum p is ∼0.16 27 . SC states with higher T c are achieved in the lightly doped region with p 0.09, similar to the SC phase diagram of hole-doped T -type La 1.8−x Eu 0.2 (Sr, Ca) x CuO 4 11,28,29 . Thus, it is important to clarify the electronic state of LESCO in superconducting T -type…”

Section: Introductionsupporting

confidence: 68%

“…Since the actual p value of 0.09 is reported for pristine LESCO with x = 0.14 26 , it can be concluded that the FL state is formed in the lower p region, contrary to that in T -type LESCO. The formation of the FL state with lower p can be attributed to the smaller size of the charge-transfer gap (∆ CT ) in the parent T *-type RECuO 11,28,29 . This similarity suggests that the doping evolution of the electronic state in LESCO with five oxygen coordination is comparable to that in La 1.8−x Eu 0.2 (Sr, Ca) x CuO 4 with four coordination, than that in LSCO with six coordination.…”

Section: Relevance To T -And T -Type Cupratesmentioning

confidence: 99%

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Fermi-liquid state in $T$*-type La$_{1-x/2}$Eu$_{1-x/2}$Sr$_x$CuO$_4$ revealed via element substitution effects on magnetism

Taniguchi,

Kudo,

Asano

et al. 2020

Preprint

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Despite its unique structural features, the magnetism of single-layered cuprate with five oxygen coordination (T *-type structure) has not been investigated thus far. Here, we report the results of muon spin relaxation and magnetic susceptibility measurements to elucidate the magnetism of T *-type La 1−x/2 Eu 1−x/2 SrxCuO4 (LESCO) via magnetic Fe-and non-magnetic Zn-substitution. We clarified the inducement of the spin-glass (SG)-like magnetically ordered state in La 1−x/2 Eu 1−x/2 SrxCuyFe1−yO4 with x = 0.24 + y, and the non-magnetic state in La 1−x/2 Eu 1−x/2 SrxCuyZn1−yO4 with x = 0.24 after the suppression of superconductivity for y ≥ 0.025. The SG state lies below ∼7 K in a wide Sr concentration range between 0.19 and 0.34 in 5% Fe-substituted LESCO. The short-range SG state is consistent with that originating from the Ruderman-Kittel-Kasuya-Yosida interaction in a metallic state. Thus, the results provide the first evidence for Fermi liquid (FL) state in the pristine T *-type LESCO. Taking into account the results of an oxygen K-edge X-ray absorption spectroscopy measurement [J. Phys. Soc. Jpn. 89, 075002 (2020)] reporting the actual hole concentrations in LESCO, our results demonstrate the existence of the FL state in a lower hole-concentration region, compared to that in T -type La2−xSrxCuO4. The emergence of the FL state in a lower hole-concentration region is possibly associated with a smaller charge transfer gap energy in the parent material with five oxygen coordination.

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Section: Introductionsupporting

confidence: 68%

Section: Relevance To T -And T -Type Cupratesmentioning

confidence: 99%

Fermi-liquid state in $T$*-type La$_{1-x/2}$Eu$_{1-x/2}$Sr$_x$CuO$_4$ revealed via element substitution effects on magnetism

Taniguchi,

Kudo,

Asano

et al. 2020

Preprint

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“…To investigate the phase diagram of HTSCs with the Nd 2 CuO 4 -type structure (so-called T'structure), T'-La 1.8 Eu 0.2 CuO 4 (T'-LECO) is one of the most appropriate materials [4,5,6,7,8]. This compound can be both electron-doped by F with O, and hole-doped by Ca or Sr with La, respectively.…”

Section: Introductionmentioning

confidence: 99%

^63,65Cu, ¹³⁹La-NMR study of Electron-doped High Temperature Cuprate Superconductor T’-La_1.8Eu_0.2CuO_4–y F_y

Fukazawa

Lee

Watai

et al. 2022

J. Phys.: Conf. Ser.

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T’-La1.8Eu0.2CuO4–y F y (0 ≤ y ≥ 0.125) was measured by 63,6BCu and 139La NMR. This material is an electron-doped high-Tc cuprate superconductor which has Nd2CuO4-type structure (so-called T’-structure). The nuclear spin-lattice relaxation rate 1/T 1 revealed that pseudogap behavior exists in the lightly electron-doped region of y ≤ 0.075 and electron doping suppresses the antiferromagnetic spin flutuations. These behaviors in electron-doped high-T c cuprate superconductor are analogous with the optimum- and over-doped region in hole-doped type. 139 La NMR spectra shows almost no antiferromagnetic region in the samples of T’-La1.8Eu0.2CuO4–y F y .

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Annealing and doping effects on magnetism for T$$^{*}$$-type (La, Eu, Sr)$$_2$$CuO$$_{4-y}$$F$$_y$$ cuprates

Xie,

Takahama,

Taniguchi

et al. 2024

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The magnetic behavior of T$$^{*}$$ ∗ -phase cuprates in the underdoped region has been studied through zero-field muon spin rotation/relaxation ($$\mu $$ μ SR) measurements. By examining the manner in which the superconducting transition temperature changes with increased fluorine substitution, we demonstrate the possibility of achieving an underdoped region in T$$^{*}$$ ∗ -La$$_{1-x/2}$$ 1 - x / 2 Eu$$_{1-x/2}$$ 1 - x / 2 Sr$$_{x}$$ x CuO$$_{4-y}$$ 4 - y F$$_{y}$$ y (LESCOF). For as-grown (AS) samples, the onset temperature for development of spin correlation is determined by $$\mu $$ μ SR measurement. We observed a substantial enhancement from $$\sim $$ ∼ 7 K (x = 0.18, y = 0) to $$\sim $$ ∼ 80 K (x = 0.18, y = 0.15) with an appearance of a magnetic order below $$\sim $$ ∼ 55 K. Thus, the magnetic order can be stabilized by underdoping in AS T$$^{*}$$ ∗ -LESCOF, similar to T-phase La$$_{2-x}$$ 2 - x Sr$$_x$$ x CuO$$_4$$ 4 . However, the damping of spin precession in the $$\mu $$ μ SR time spectra appears to be significant than in La$$_2$$ 2 CuO$$_4$$ 4 (LCO), suggesting the presence of inhomogeneous magnetism. In addition, the unrecovered normalized time spectrum to 1/3 along the time axis indicates a dynamical nature of magnetism. These magnetic behavior disappears with oxidation annealing, even in the lightly hole-doped sample. The absence of static magnetism in the oxidation-annealed T$$^{*}$$ ∗ -LESCOF could be attributed to the structural effect, as the physical properties of the T$$^{\prime }$$ ′ -phase cuprates has been discussed in terms of oxygen coordination around the Cu ion.

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Electron-Doping Effect on T_c in the Undoped (Ce-Free) Superconductor T′-La_1.8Eu_0.2CuO₄ Studied by the Fluorine Substitution for Oxygen

Cited by 8 publications

References 27 publications

Fermi-liquid state in $T$*-type La$_{1-x/2}$Eu$_{1-x/2}$Sr$_x$CuO$_4$ revealed via element substitution effects on magnetism

Fermi-liquid state in $T$*-type La$_{1-x/2}$Eu$_{1-x/2}$Sr$_x$CuO$_4$ revealed via element substitution effects on magnetism

^63,65Cu, ¹³⁹La-NMR study of Electron-doped High Temperature Cuprate Superconductor T’-La_1.8Eu_0.2CuO_4–y F_y

Annealing and doping effects on magnetism for T$$^{*}$$-type (La, Eu, Sr)$$_2$$CuO$$_{4-y}$$F$$_y$$ cuprates

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Electron-Doping Effect on Tc in the Undoped (Ce-Free) Superconductor T′-La1.8Eu0.2CuO4 Studied by the Fluorine Substitution for Oxygen

Cited by 8 publications

References 27 publications

Fermi-liquid state in $T$*-type La$_{1-x/2}$Eu$_{1-x/2}$Sr$_x$CuO$_4$ revealed via element substitution effects on magnetism

Fermi-liquid state in $T$*-type La$_{1-x/2}$Eu$_{1-x/2}$Sr$_x$CuO$_4$ revealed via element substitution effects on magnetism

63,65Cu, 139La-NMR study of Electron-doped High Temperature Cuprate Superconductor T’-La1.8Eu0.2CuO4–y F y

Annealing and doping effects on magnetism for T$$^{*}$$-type (La, Eu, Sr)$$_2$$CuO$$_{4-y}$$F$$_y$$ cuprates

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Electron-Doping Effect on T_c in the Undoped (Ce-Free) Superconductor T′-La_1.8Eu_0.2CuO₄ Studied by the Fluorine Substitution for Oxygen

^63,65Cu, ¹³⁹La-NMR study of Electron-doped High Temperature Cuprate Superconductor T’-La_1.8Eu_0.2CuO_4–y F_y