Microstructure of laser-ablated superconducting La2CuO4Fx thin films on SrTiO3

2001 ◽  
Vol 16 (11) ◽  
pp. 3309-3316 ◽  
Author(s):  
G. Kong ◽  
M. O. Jones ◽  
J. S. Abell ◽  
P. P. Edwards ◽  
S. T. Lees ◽  
...  
Keyword(s):  
Thin Films ◽  
Lattice Mismatch ◽  
Microstructural Analysis ◽  
Stacking Faults ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Elemental Fluorine ◽  
Deposit Surface ◽  
Film Substrate ◽  
Post Deposition

Thin films of lanthanum cuprate were grown on SrTiO3 substrates by pulsed laser deposition and made superconducting (Tc ∼ 38 K) through the process of post-deposition fluorination using elemental fluorine. A microstructural analysis showed that the [110] zone of the film grows parallel to the [100] zone of the SrTiO3 substrate, reducing the lattice mismatch from 37.5% to 2.4%. At the film–substrate interface there is an intermediate layer 3–4 nm thick and twin-related grains emanate from this region. Stacking faults are present in the bulk of the film, with misoriented subgrains present at the deposit surface.

Pulsed Laser Deposition of BaxSr1-xTiO3 Thin Films for Frequency Agile Microwave Electronics

1998 ◽  
Vol 526 ◽  
Author(s):  
W. Chang ◽  
J. S. Horwitz ◽  
J. M. Pond ◽  
S. W. Kirchoefer ◽  
D B. Chrisey
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Lattice Mismatch ◽  
Pulsed Laser ◽  
Dielectric Behavior ◽  
Laser Deposition ◽  
Film Stress ◽  
Bst Films ◽  
The Difference ◽  
Film Substrate

AbstractOriented, single phase thin films (~5000Å thick) of BaxSr1-xTiO3 (BST) have been deposited on to (100) MgO and LaAlO3 (LAO) single crystal substrates using pulsed laser deposition (PLD). A strong correlation is observed between the microstructure of the deposited film and the dielectric tuning and loss at microwave frequencies. Microstructural defects observed in as deposited films include strain, due to film substrate lattice mismatch and oxygen and cation vacancies. Compensation of the ablation target with excess Ba and Sr is observed to increase the dielectric constant and to reduce the dielectric loss. Post-deposition, bomb annealing of films at high temperatures (1250°C) is observed to fill oxygen vacancies and increase grain size. The difference in the dielectric behavior for as-deposited and low temperature annealed BST films on MgO and BST films on LAO is observed and may be attributed to the differences in film stress. A further improvement in the dielectric behavior is observed by the addition of donor/acceptor dopants such as Mn. The data shows that ferroelectric thin films can be used to build tunable microwave circuits that offer significant performance advantages over devices made from conventional semiconducting materials.

Luminescent Characteristics of Pulsed Laser Deposited Epitaxial Eu-Doped Y2O3 Films

1999 ◽  
Vol 574 ◽  
Author(s):  
D. Kumar ◽  
K. G. Cho ◽  
Zhang Chen ◽  
V. Craciun ◽  
P. H. Holloway ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Epitaxial Growth ◽  
Yttrium Oxide ◽  
Lattice Mismatch ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Deposition Technique ◽  
Deposition Parameters

AbstractThe growth, structural and cathodoluminescent (CL) properties of europium activated yttrium oxide (Eu:Y2O3) thin films are reported. The Eu:Y2O3 films were grown in-situ using a pulsed laser deposition technique. Our results show that Eu:Y2O3 films can grow epitaxially on (100) LaAlO3 substrates under optimized deposition parameters. The epitaxial growth of Eu:Y2O3 films on LaAlO3, which has a lattice mismatch of ∼ 60 %, is explained by matching of the atom positions in the lattices of the film and the substrate after a rotation. CL data from these films are consistent with highly crystalline Eu:Y2O3 films with an intense CL emission at 611 nm.

Colossal Temperature Coefficient of Resistivity in Epitaxial Colossal Magnetoresistive La0.67Ca0.33MnO3 Films

2001 ◽  
Vol 666 ◽  
Author(s):  
S.I. Khartsev ◽  
A.M. Grishin
Keyword(s):  
Temperature Coefficient ◽  
Lattice Mismatch ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Processing Conditions ◽  
Colossal Magnetoresistive ◽  
Lcmo Film ◽  
Post Annealing ◽  
Temperature Coefficient Of Resistivity ◽  
Film Substrate

ABSTRACTEpitaxial La0.67Ca0.33MnO3(LCMO) films have been grown by pulsed laser deposition technique on three single crystal substrates: LaAlO3, SrTiO3, and NdGaO3 having lattice mismatch with LCMO film of + 1.26 %, - 0.9 %, and + 0.18 %. We found the transport colossal magnetoresistive (CMR) properties were improved with the reduction of a film/substrate mismatch. Processing conditions for LCMO film on NdGaO3substrate were optimized as well as post-annealing process was employed to achieve a superior temperature coefficient of resistivity TCR = 35 %K−1 and the magnetoresistance MR = 66 % at 7 kOe. To our knowledge, these are the record CMR parameters achieved so far.

Influence of stress on structural and dielectric anomaly of Bi2(Zn1/3Ta2/3)207 thin films

2005 ◽  
Vol 875 ◽  
Author(s):  
Jun Hong Noh ◽  
Hee Bum Hong ◽  
Kug Sun Hong
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Interfacial Layer ◽  
Monoclinic Phase ◽  
Lattice Mismatch ◽  
Pulsed Laser ◽  
Dielectric Anomaly ◽  
Laser Deposition ◽  
Cubic Phase ◽  
Si Substrates

AbstractBi2(Zn1/3Ta2/3)2O7 (BZT) thin films were grown on the (111) oriented Pt/TiOx/SiO2/Si substrates using a pulsed laser deposition (PLD) technique. BZT thin films deposited at an oxygen partial pressure of 400 mTorr have the non-stoichiometric anomalous cubic phase despite the BZT target was the monoclinic phase. Compositions, the lattice mismatch, the interfacial layer and the residual stress in the film were investigated as the factors which may affect the formation of the anomalous cubic phase. Among them, the coherent interfacial layer which formed at high oxygen pressures resulted in the formation of the cubic phase by reducing the internal stress.

Crystallization of yttrium-iron garnet (YIG) in thin films: Nucleation and growth aspects

2007 ◽  
Vol 1036 ◽  
Author(s):  
Michael V. Zaezjev ◽  
Manda Chandra Sekhar ◽  
Marcello Ferrera ◽  
Luca Razzari ◽  
Barry M Holmes ◽  
...  
Keyword(s):  
Thin Films ◽  
Yttrium Iron Garnet ◽  
Single Phase ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Yttrium Iron ◽  
Iron Garnet ◽  
Parasitic Phase ◽  
Deposited Films ◽  
Post Deposition

AbstractWe have studied the crystallization of the yttrium - iron garnet (Y3Fe5O12, YIG) polycrystalline phase in thin films fabricated by means of pulsed laser deposition . Films were deposited on MgO substrates in vacuum, in argon, and in oxygen. A subsequent post-deposition heat treatment (annealing) was done at 800°C in air. We have shown that the crystallization of YIG was precluded by co-existent parasitic phases present in the as-deposited films. Specifically, the growth of the parasitic phase needs to be suppressed in order to get a single-phase polycrystalline YIG. Lowering the substrate temperature has been shown to be a simple and efficient way to suppress the growth of parasitic phase and to obtain good quality YIG films after thermal treatment. This procedure has been demonstrated to be successful even when the YIG films were grown in vacuum and their composition was significantly out of stoichiometry.

Control of Preferential Orientation of La1-xSrxMnO3 Thin Films by Pulsed Laser Deposition

2016 ◽  
Vol 697 ◽  
pp. 756-760 ◽  
Author(s):  
Ya Xiang Zhu ◽  
Chuan Bin Wang ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Lattice Mismatch ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Preferential Orientation ◽  
Orientation Relationships ◽  
Pole Figures ◽  
Small Lattice ◽  
Xrd Patterns

La1-xSrxMnO3 (LSMO) thin films were grown on (100)- and (110)-oriented MgO substrates by pulsed laser deposition, so as to control the preferential orientation of the films. At the optimum deposition temperature (Td = 923K), LSMO thin films with a dense texture and a smooth surface were prepared. The XRD patterns and X-ray pole figures indicated that the LSMO thin films were epitaxially grown on MgO substrates, due to the small lattice mismatch between the films and substrates The possible orientation relationships were found to be LSMO (100) [100] // MgO (100) [100] and LSMO (110) [110] // MgO (110) [110], as for the (100) and (110) MgO substrates, respectively.

The Structure and Electric Field Dependent Dielectric Properties of Annealed Sr1−xBaxTio3 Ferroelectric Thin Films

1995 ◽  
Vol 401 ◽  
Author(s):  
L.A. Knauss ◽  
J.M. Pond ◽  
J.S. Horwitz ◽  
C.H. Mueller ◽  
R.E. Treece ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Single Phase ◽  
Pulsed Laser ◽  
Lattice Parameter ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Deposited Films ◽  
Post Deposition

AbstractThe effect of a post deposition anneal on the structure and dielectric properties of epitaxial Sr1−x, BaxTiO3 (SBT) thin films with x = 0.35, 0.50 and 0.60 has been measured. The films were grown by pulsed laser deposition on LaAlO3(001) substrates at 750°C in 350 mTorr of oxygen. The asdeposited films were single phase, (001) oriented with 0)-scan widths for the (002) reflection between 0.160 and 0.50'. The dielectric properties of the as-deposited films exhibit a broad temperature dependence and a peak which is as much as 50 K below the peak in bulk SBT. Also, the lattice parameter, as measured by x-ray diffraction, of the as-deposited films was larger than the bulk indicating strain in the films. The as-deposited films were annealed for 8 hours at 900°C in oxygen. The dielectric properties of the annealed films were closer to that of bulk SBT and the lattice parameter was closer to the bulk lattice parameter indicating a reduction of strain. Annealing of as-deposited films also resulted in an increased dielectric tuning without increased dielectric loss.

β-FeSi2 thin-films grown by a pulsed laser deposition

2000 ◽  
Vol 648 ◽  
Author(s):  
Shin-ichiro Uekusa ◽  
Yasuharu Watanabe ◽  
Yasuhiro Aida ◽  
Noboru Miura
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Lattice Mismatch ◽  
Pulsed Laser ◽  
Band Gap Energy ◽  
Laser Deposition ◽  
Carrier Distribution ◽  
Van Der Pauw ◽  
P Type

AbstractOrthorhombic β-FeSi2 thin-films were prepared on Si(100) and Si(111) substrates by a pulsed laser deposition method. When the substrate temperature was 500°C, β-FeSi2 thin-films were grown on Si(100) and Si(111) substrates. The thin-films grown on Si(100) and Si(111) substrates were polycrystalline and monocrystalline structures, respectively. The values of band-gap energy calculated from transmittance measurements were 0.71-0.72 eV. From Raman scattering measurements, it was found that the distortion due to the lattice mismatch between a β-FeSi2 thin-film and a Si substrate originates in the β-FeSi2/n-Si interface. Moreover, the fine crystals of β-FeSi2 existed in an amorphous thin-film which was grown on Si(111) substrate at room temperature (RT).From van der Pauw measurements, conduction type, carrier concentration and Hall mobility were p-type, 1018-1021 cm−3 and 200-500 cm2/Vsec, respectively. The p-n diode characteristics of these heterostructure diodes were investigated by I-V and C-V measurements. The results indicate that the carrier distribution agrees with an ideal one-sided slope junction.

Dielectric and Structural Properties of (100) KTa1−xNbxO3 Films Grown on MgO, LaAIO3 and SrTiO3 Substrates by Pulsed Laser Deposition

1997 ◽  
Vol 493 ◽  
Author(s):  
Wontae Chang ◽  
Adriaan C. Carter ◽  
James S. Horwitz ◽  
Steven W. Kirchoefer ◽  
Jeffrey M. Pond ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Electric Field ◽  
Pulsed Laser Deposition ◽  
Lattice Mismatch ◽  
Pulsed Laser ◽  
Atomic Ratio ◽  
Film Deposition ◽  
Laser Deposition ◽  
Bias Electric Field ◽  
Post Deposition

ABSTRACTKTa1−xNbxO3 (KTN) thin films (-6000 Å) were grown on (100) MgO, (100) LaAlO3 (LAO), and (100) SrTiO3(STO) substrates by pulsed laser deposition (PLD). Deposited films were smooth, single phase and exclusively (100) oriented. KTN films deposited on MgO and LAO substrates were easily cracked after deposition or post deposition heat treatment. The film deformation appeared to be caused by strain due to the lattice mismatch between the film and the substrate. A thin buffer layer of ∼100 Å was used to eliminate the cracking problem. The high volatility of K at the film deposition temperature required excess K to be added to the ablation target. Sintering of the target and post-deposition annealing of the films were done in a sealed Pt coated stainless steel container. Rutherford backscattering showed the films to have a 1 to 1 atomic ratio of K to Ta + Nb. On top of the KTN films, Ag interdigitated capacitors were deposited. Room temperature measurements of capacitance and dielectric loss as a function of bias electric field (0 -80 kV/cm) at 1 to 20 GHz were made. Capacitance and dielectric loss measurements were made as a function of temperature and bias electric field at one MHz and as a function of temperature and frequency at 0V DC bias. The results show the strong potential of KTN for use in frequency agile microwave electronics.

Sign in / Sign up

Export Citation Format

Share Document