Artificial Control of Magnetic and Magnetoresistive Properties in the Perovskite Manganites Superlattices and Their Multilayers With Organics

1999 ◽  
Vol 602 ◽  
Author(s):  
H. Tabata ◽  
K. Ueda ◽  
H. Matsui ◽  
H. Saeki ◽  
T. Kawai
Keyword(s):  
Lattice Strain ◽  
Copper Phthalocyanine ◽  
Frustration Effect ◽  
Laser Deposition ◽  
Perovskite Manganites ◽  
Electric Field Effect ◽  
Spin Frustration ◽  
Piezo Effect ◽  
Magnetic Ions ◽  
Artificial Control

AbstractArtificial superlattice of LaFeO3-LaMnO3 have been formed on SrTiO3(111), (110) and (100) substrates with various stacking periodicity using pulsed laser deposition. Their magnetic properties have been controlled by altering the ordering of magnetic ions (Fe or Mn). Charge disproportionate behaviors are also observed in these superlattices. For the superlattices on (111) plane, all the samples showed ferromagnetic (or ferrimagnetic) behaviors and the same Curie temperature of 230K. In the case of other superlattices formed on (110) and (100), oh the other hand, the increase of the spin frustration effect between LFO-LMO interface with decrease of the stacking periodicity causes reduction of Tc and magnetization. Specially, spin glass like behaviors observed in the superlattices of less than 3/3 stacking periodicity Furthermore, we have constructed heterostructures of Organic/Inorganic multilayers with a sequence of Copper phthalocyanine(CuPc), BaTiO3 and (LaSr)MnO3. In this system, magnetoresistant properties have been controlled by the photo irradiation through the lattice strain and/or induced charges caused by the piezo effect and electric field effect. That is magnetoresistance in the (LaSr)MnO3 layer can be controlled by the shining the light.

Study the Nonlinearity Characteristics of Organic-Semiconductor (CuPc) Prepared Via Pulsed Laser Deposition Technique with Different Thickness

2019 ◽  
Vol 27 ◽  
pp. 11-20 ◽  
Author(s):  
Mohammed T. Hussein ◽  
Reem R. Mohammed
Keyword(s):  
Refractive Index ◽  
Absorption Spectrum ◽  
Pulsed Laser Deposition ◽  
Copper Phthalocyanine ◽  
Wave Length ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Deposition Technique ◽  
Linear Refractive Index ◽  
Non Linear

The optical absorption spectrum, Photoluminesces, and non-linear optical properties for Copper Phthalocyanine (CuPc) thin films (150,300 and 450 nm) respectively have been investigated via pulsed laser deposition technique. The absorption spectrum indicted that there are two bands one in UV around 330 nm which called B-band and the second in Visible around 650nm which called Q-band. Photoluminescence spectrum related to deposit samples has been determined with different thicknesses. From closed and open aperture Z-scan data non-linear absorption coefficient and non-linear refractive index have been calculated respectively using He-Ne laser which have beam waist of (24.2 μm), wave-length of (632.8 nm) and Rayleigh thickness was 2.9 mm. Through dividing closed by open apertures, non-linear refractive index was calculated accurately. Finally, the study also showed the suitability of the deposited films as an optical limiter at the wavelength 632.8 nm.

scholarly journals Suppression of phase separation and giant enhancement of superconducting transition temperature in FeSe1−xTex thin films

2015 ◽  
Vol 112 (7) ◽  
pp. 1937-1940 ◽  
Author(s):  
Yoshinori Imai ◽  
Yuichi Sawada ◽  
Fuyuki Nabeshima ◽  
Atsutaka Maeda
Keyword(s):  
Phase Separation ◽  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Lattice Strain ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Separation Region ◽  
Superconducting Transition ◽  
Key Factors ◽  
Maximum Value

We demonstrate the successful fabrication on CaF2 substrates of FeSe1−xTex films with 0≤x≤1, including the region of 0.1≤x≤0.4, which is well known to be the “phase-separation region,” via pulsed laser deposition that is a thermodynamically nonequilibrium method. In the resulting films, we observe a giant enhancement of the superconducting transition temperature, Tc, in the region of 0.1≤x≤0.4: The maximum value reaches 23 K, which is ∼1.5 times as large as the values reported for bulk samples of FeSe1−xTex. We present a complete phase diagram of FeSe1−xTex films. Surprisingly, a sudden suppression of Tc is observed at 0.1<x<0.2, whereas Tc increases with decreasing x for 0.2≤x<1. Namely, there is a clear difference between superconductivity realized in x=0−0.1 and in x≥0.2. To obtain a film of FeSe1−xTex with high Tc, the controls of the Te content x and the in-plane lattice strain are found to be key factors.

Hybrid Structure of Organic-Inorganic Photovoltaic Fast Carrier Transport

2020 ◽  
Vol 30 ◽  
pp. 19-26
Author(s):  
Mohammed T. Hussein ◽  
Fouad A. Senaed
Keyword(s):  
Carrier Transport ◽  
Copper Phthalocyanine ◽  
Pulsed Laser ◽  
Hybrid Structure ◽  
Laser Deposition ◽  
Visible Absorption ◽  
Carrier Transfer ◽  
Ft Ir ◽  
Organic Copper ◽  
Different Thickness

Hybrid organic Copper phthalocyanine (CuPc) –inorganic Cadmium Sulfide (CdS), double layered structures were deposited on glass substrate at different thickness using Pulsed Laser Deposition (PLD) with Q-Switching Nd: YAG laser with energy (240,500 mJ) at (25 Celsius) and within vacuum conditions of (10-3 torr). The photoluminescence (PL) is showing that the CdS quenches emissions from CuPc indicating the carrier transfer to the CdS. Also, the CuPc/CdS hybrid structures have the capability for various absorptions as can be seen in the ultraviolet-visible absorption researches and the charge carrier extractions from PL analysis have been adequate for the solar cell applications. FT-IR spectra have been specified for CdS and CuPc.

Aging Characteristics of Ferroelectric Epitaxial BaTiO3/YBa2Cu3O7 Heterostructures

1994 ◽  
Vol 341 ◽  
Author(s):  
Samuel D. Harkness ◽  
J. W Viatella ◽  
V. Nagabushnam ◽  
R. K. Singh
Keyword(s):  
Lattice Strain ◽  
Microstructural Analysis ◽  
Laser Deposition ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
Impedance Analyzer ◽  
Aging Rate ◽  
X Ray ◽  
Aging Rates ◽  
D 02

AbstractThe nature of ferroelectric aging of epitaxial BaTiO3YBa2Cu3O7 heterostructures grown by laser deposition was investigated as a function of rricrostructure in the dielctric layer. Molar amounts of SrTiO3 were then substitutionally added to analyze the effect on the rnicrostructure and electrical properties. Corresponding shifts in c/a ratio and curie temperature were correlated to changes in aging rate (%δC/decade time). Microstructural analysis was provided by high-resolution x-ray diffraction (HRXRD), and Rutherford backscattering spectroscopy (RBS). Results indicate a moderate upward shift in c/a ratios from theoretical values due to increasing lattice strain across the bilayer interface. Minimum channel yields in RBS spectra were maintained between 6–8% for BaTiO3 purities above 60 %. Dielectric measurements were conducted using an impedance analyzer equipped with an isothermal chamber capable of maintaining ±1°C. The dielectric properies were consistent with c-axis oriented BaTiO3 values (k=120, D=.02)Minimum aging rates are observed at the lower c/a ratio compositions to be as low as .07%δC/decade.

Epitaxial growth and in-plane dielectric properties of DyMnO3 by pulsed-laser deposition

2019 ◽  
Vol 33 (28) ◽  
pp. 1950333
Author(s):  
Weitian Wang
Keyword(s):  
Thin Film ◽  
Dielectric Properties ◽  
Pulsed Laser Deposition ◽  
Complex Permittivity ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Perovskite Manganites ◽  
Dielectric Relaxations ◽  
Measuring Frequency ◽  
Relationship Of

Perovskite manganites DyMnO3 thin film was grown epitaxially on LaAlO3 (110) substrate by using pulsed-laser deposition (PLD) technique. The film showed perfectly orthorhombic crystallization and was well-aligned with the substrates. The in-plane dielectric properties of DyMnO3 film were measured as functions of temperature (80–300 K) and frequency (120–100 kHz) by using parallel-plate interdigital electrodes (IDEs). Distinct transitions can be observed in the complex permittivity and loss tangent and the respective peaks shifted to higher temperatures as the measuring frequency increased. By the Arrhenius plots, the determined activation energy of the thermally activated dielectric relaxations was about 0.20 eV. According to the relationship of the real and imaginary parts of the complex permittivity, the in-plane dielectric properties of epitaxial DyMnO3 thin film can be described as the universal dielectric response (UDR) behavior.

scholarly journals Colossal Isotope Shift of the Metal-Insulator Transition Temperature in Epitaxial Thin Films of (La1-y Pry)0·7Ca0·3MnO3

1999 ◽  
Vol 52 (2) ◽  
pp. 269 ◽  
Author(s):  
O. Yu. Gorbenko ◽  
A. R. Kaul ◽  
N. A. Babushkina ◽  
L. M. Belova ◽  
B. Guettler
Keyword(s):  
Lattice Dynamics ◽  
Room Temperature ◽  
Lattice Strain ◽  
Insulator Transition ◽  
Perovskite Manganites ◽  
Epitaxial Thin Films ◽  
Raman Spectrometry ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Oxygen Isotope Exchange

A colossal shift of the maximum resistivity temperature induced by oxygen isotope exchange was registered for 60 nm thick films of the solid solution La0·35Pr0·35Ca0·3MnO3 on perovskite substrates. The magnitude of the effect depends on lattice strain resulting in the largest shift for the film on LaAlO3: the 16O sample showed a metal-insulator transition at 182 K, whereas the 18O sample was insulating down to 4·2 K, which is the highest difference ever reported for CMR manganites. An XRD and Raman spectrometry study indicates no difference in chemical composition or structure for the 18O and 16O samples at room temperature. The results are consistent with the model coupling the metal-insulator transition in the perovskite manganites to the lattice dynamics.

Electric field effect in pulsed laser deposition of epitaxial ZnO thin film

2004 ◽  
Vol 79 (4-6) ◽  
pp. 807-809 ◽  
Author(s):  
C. Hirose ◽  
Y. Matsumoto ◽  
Y. Yamamoto ◽  
H. Koinuma
Keyword(s):  
Thin Film ◽  
Electric Field ◽  
Pulsed Laser Deposition ◽  
Field Effect ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Electric Field Effect ◽  
Zno Thin Film
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