Growth and properties of La2−<i>x</i>Sr<i>x</i>CuO4 films

Trofimov, I. E.; Johnson, L. W.; Ramanujachary, Kandalam V.; Guha, Saikat; Harrison, Mark; Greenblatt, Martha; Cieplak, Marta Z.; Lindenfeld, P.

doi:10.1063/1.112671

Cited by 52 publications

(32 citation statements)

References 9 publications

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“…The best quality LSCO thin films were grown either by ozone or atomic oxygen assisted molecular beam epitaxy (MBE) or by e-beam co-evaporation techniques 11,12 . To date there exist only few reports of La 1.85 Sr 0.15 CuO 4 films with bulk superconducting properties and high T c values that have been grown with pulsed laser deposition (PLD) technique [13][14][15] . Those films have been deposited in molecular O 2 environment and have either been oxygenated by slow cooling inside the growth chamber in a gas mixture of oxygen and ozone or by performing an ex-situ post-growth annealing treatment in high pressure oxygen atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Structural, magnetic, and superconducting properties of pulsed-laser-deposition-grownLa1.85Sr0.15CuO4
Das
¹
,
Sen
²
,
Marozau
³

et al. 2014
Phys. Rev. B
11
1
18
0
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Epitaxial La1.85Sr0.15CuO4/La 2/3 Ca 1/3 MnO3 (LSCO/LCMO) superlattices (SL) on (001)-oriented LaSrAlO4 substrates have been grown with pulsed laser deposition (PLD) technique. Their structural, magnetic and superconducting properties have been determined with in-situ reflection high energy electron diffraction (RHEED), x-ray diffraction, specular neutron reflectometry, scanning transmission electron microscopy (STEM), electric transport, and magnetization measurements. We find that despite the large mismatch between the in-plane lattice parameters of LSCO (a = 0.3779 nm) and LCMO (a = 0.387 nm) these superlattices can be grown epitaxially and with a high crystalline quality. While the first LSCO layer remains clamped to the LSAO substrate, a sizeable strain relaxation occurs already in the first LCMO layer. The following LSCO and LCMO layers adopt a nearly balanced state in which the tensile and compressive strain effects yield alternating in-plane lattice parameters with an almost constant average value. No major defects are observed in the LSCO layers, while a significant number of vertical antiphase boundaries are found in the LCMO layers. The LSCO layers remain superconducting with a relatively high superconducting onset temperature of T onset c ≈ 36 K. The macroscopic superconducting response is also evident in the magnetization data due to a weak diamagnetic signal below 10 K for H ab and a sizeable paramagnetic shift for H c that can be explained in terms of a vortex-pinning-induced flux compression. The LCMO layers maintain a strongly ferromagnetic state with a Curie temperature of T Curie ≈ 190 K and a large low-temperature saturation moment of about 3.5(1) µB. These results suggest that the LSCO/LCMO superlattices can be used to study the interaction between the antagonistic ferromagnetic and superconducting orders and, in combination with previous studies on YBCO/LCMO superlattices, may allow one to identify the relevant mechanisms.

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Section: Introductionmentioning

confidence: 99%

Structural, magnetic, and superconducting properties of pulsed-laser-deposition-grownLa1.85Sr0.15CuO4
Das
¹
,
Sen
²
,
Marozau
³

et al. 2014
Phys. Rev. B
11
1
18
0
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“…[13]. One film is overdoped, with a nominal x=0.23 and T c (midpoint) of 19 K. The other is underdoped, with a nominal x=0.13.…”

mentioning

confidence: 99%

“…One film is overdoped, with a nominal x=0.23 and T c (midpoint) of 19 K. The other is underdoped, with a nominal x=0.13. This film was annealed in high-pressure oxygen [13] yielding a T c (midpoint) of 28 K. The films were patterned by photolithography into a conventional Hall bar with a center strip 0.2 mm wide. Silver contact pads were evaporated onto the arms and gold wires attached to them using silver epoxy.…”

mentioning

confidence: 99%

Normal-state Hall effect and the insulating resistivity of high-Tccuprates at low temperatures

Ando

Boebinger²,

Passner³

et al. 1997

Phys. Rev. B

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The normal-state Hall coefficient RH and the in-plane resistivity ρ ab are measured in La-doped Bi2Sr2CuOy (Tc ≃ 13 K) single crystals and La2−xSrxCuO4 thin films by suppressing superconductivity with 61-T pulsed magnetic fields. In contrast to data above Tc, the RH below ∼ 10 K shows little temperature dependence in all the samples measured, irrespective of whether ρ ab exhibits insulating or metallic behavior. Thus, whatever physical mechanism gives rise to insulating behavior in the low-temperature normal state, it leaves the Hall conductivity relatively unchanged.PACS numbers: 74.25.Fy, 74.20.Mn, 74.72.Hs, 71.10.Hf Application of a pulsed high magnetic field to suppress superconductivity in the high-T c cuprates has opened up the possibility for measurements of normal-state transport at low temperatures. This regime has been rather unexplored due to the extremely high H c2 of the cuprates. Thus far the anisotropic normal-state resistivity has been measured in La 2−x Sr x CuO 4 (LSCO) [1,2] and La-doped Bi 2 Sr 2 CuO y (Bi-2201) [3] down to subkelvin temperatures using 61-T pulsed magnetic fields.One of the surprising findings in the low-temperature normal-state resistivity of LSCO is an unusual log(1/T ) divergence of both in-plane (ρ ab ) and c-axis resistivity (ρ c ) of underdoped samples. Similar divergence of resistivity that is consistent with log(1/T ) is also found in disordered Bi-2201 [3], where the dynamic range of the divergence is generally smaller than in underdoped LSCO, where the increase of ρ ab can be as large as a factor of three. Although the origin of the unusual log(1/T ) behavior is not yet clear, there are several proposed explanations, some of which involve the localization of the charge-carrying quasi-particles [4,5], others of which involve the suppression of the two-dimensional density of states near the Fermi energy. In this latter scenario, the low-temperature insulating behavior in the cuprates might result from conventional disorder-enhanced electron interactions [6], from the temperature-dependent impurity scattering time in the marginal Fermi liquid [7], or from the existence of a pseudo-gap in the underdoped high-T c cuprates [8].In conventional physics of disordered metals in twodimensions, both weak localization and electron-electron interactions give rise to identical log(1/T ) corrections to the resistivity. Measurement of the Hall coefficient R H is useful in separating these two physical mechanisms [6]: weak localization does not affect R H , while interactions lead to corrections in R H which are two times larger than the corrections to the resistivity. The physics of the cuprates is expected to be very different from that of conventional disordered metals. Indeed, three independent reports of logarithmic behavior in underdoped cuprates provide three separate arguments against interpretations involving conventional weak localization [1,9,10]. Nevertheless, measurement of the Hall effect down to low temperatures could help resolve which of the proposed physical mech...

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“…To get a higher T C , the oxygen content between the two La-O layers should be increased by a post-annealing process. According to the study proposed, a higher T C may be achieved by high-pressure annealing in oxygen [10]. To let the film be fully oxygenated, at the end of the deposition the film is in situ annealed in the chamber under 700 Torr oxygen, then slowly cooled down to room temperature at a rate of 4 • C/min.…”

Section: Resultsmentioning

confidence: 99%

The effect of substrate and annealing temperatures on the microstructure of La1.85Sr0.15CuO4 thin film in pulsed electron deposition process

Chen

Liu

Zeng

et al. 2008

Journal of Alloys and Compounds

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Growth and properties of La2−xSrxCuO4 films

Cited by 52 publications

References 9 publications

Structural, magnetic, and superconducting properties of pulsed-laser-deposition-grownLa1.85Sr0.15CuO4
Das
¹
,
Sen
²
,
Marozau
³

et al. 2014
Phys. Rev. B
11
1
18
0
View full text Add to dashboard Cite

Structural, magnetic, and superconducting properties of pulsed-laser-deposition-grownLa1.85Sr0.15CuO4
Das
¹
,
Sen
²
,
Marozau
³

et al. 2014
Phys. Rev. B
11
1
18
0
View full text Add to dashboard Cite

Normal-state Hall effect and the insulating resistivity of high-Tccuprates at low temperatures

The effect of substrate and annealing temperatures on the microstructure of La1.85Sr0.15CuO4 thin film in pulsed electron deposition process

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Growth and properties of La2−xSrxCuO4 films

Cited by 52 publications

References 9 publications

Structural, magnetic, and superconducting properties of pulsed-laser-deposition-grownLa1.85Sr0.15CuO4Das1, Sen2, Marozau3 et al. 2014Phys. Rev. B111180View full textAdd to dashboardCite

Structural, magnetic, and superconducting properties of pulsed-laser-deposition-grownLa1.85Sr0.15CuO4Das1, Sen2, Marozau3 et al. 2014Phys. Rev. B111180View full textAdd to dashboardCite

Normal-state Hall effect and the insulating resistivity of high-Tccuprates at low temperatures

The effect of substrate and annealing temperatures on the microstructure of La1.85Sr0.15CuO4 thin film in pulsed electron deposition process

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Product

Resources

About

Structural, magnetic, and superconducting properties of pulsed-laser-deposition-grownLa1.85Sr0.15CuO4
Das
¹
,
Sen
²
,
Marozau
³

et al. 2014
Phys. Rev. B
11
1
18
0
View full text Add to dashboard Cite

Structural, magnetic, and superconducting properties of pulsed-laser-deposition-grownLa1.85Sr0.15CuO4
Das
¹
,
Sen
²
,
Marozau
³

et al. 2014
Phys. Rev. B
11
1
18
0
View full text Add to dashboard Cite