In-Situ Optical Diagnostics During Pulsed-Laser Deposition of Magnetoresistive La-Ca-Mn-O Films on Silicon Substrates

1996 ◽  
Vol 441 ◽  
Author(s):  
P.-J. Kung ◽  
J. E. Cosgrove ◽  
K. Kinsella ◽  
D. G. Hamblen

AbstractDuring pulsed-laser deposition of La0.67Ca0.33MnO3 films on silicon substrates, a system that consists of visible optical-emission spectroscopy (OES) and Fourier transform infrared (FT-IR) spectroscopy is employed to perform in-situ diagnosis of the laser-induced plume and to monitor the substrate temperature and the film thickness. The effects of oxygen pressure, laser fluence, and distance from the target surface on emission spectra were studied. In FT-IR measurements, the slopes of the reflectance versus wavenumber curves were observed to increase with film thickness and hence with time, which provides end-point detection during the film growth. La0.67Ca0.33MnO3 films with (100), (110), and mixed orientations, depending on the substrate temperature, were deposited on yttria-stabilized zirconia (YSZ) buffered Si(100) and Si(111) substrates. In a magnetic field of 5 T, the maximum magnetoresistance (MR) values of 250% at 195 K and 164% at 140 K were observed in the as-deposited (110) and (100) films, respectively.

1994 ◽  
Vol 361 ◽  
Author(s):  
William Jo ◽  
T.W. Noh

ABSTRACTUsing pulsed laser deposition, Bi4Ti3O12 thin films were grown on (0001) and (1102) surfaces of Al2O3. Substrate temperature from 700 to 800 °C and oxygen pressure from 50 to 1000 mtorr were varied, and their effects on Bi4Ti3O12 film growth behavior was investigated. Only for a narrow range of deposition parameters, can highly oriented Bi4Ti3O12(104) films be grown on Al2O3(0001). Further, epitaxial BTO(004) films can be grown on Al2O3(1102). The growth behavior of preferential BTO film orientations can be explained in terms of atomic arrangements in the Bi4Ti3O12 and the Al2O3 planes.


2020 ◽  
Author(s):  
Jérôme Wolfman ◽  
Beatrice Negulescu ◽  
Antoine Ruyter ◽  
Ndioba Niang ◽  
Nazir Jaber

In this chapter we will describe a new development of combinatorial pulsed laser deposition (CPLD) which targets the exploration of interface libraries. The idea is to modulate continuously the composition of interfaces on a few atomic layers in order to alter their functional properties. This unique combinatorial synthesis of interfaces is possible due to very specific PLD characteristics. The first one is its well-known ability for complex oxide stoichiometry transfer from the target to the film. The second one is the layer by layer control of thin film growth at the atomic level using in-situ RHEED characterization. The third one relates to the directionality of the ablated plume which allows for selective area deposition on the substrate using a mobile shadow-mask. However PLD also has some limitations and important PLD aspects to be considered for reliable CPLD are reviewed. Multiple examples regarding the control of interface magnetism in magnetic tunnel junctions and energy band and Schottky barrier height tuning in ferroelectric tunable capacitors are presented.


2002 ◽  
Vol 17 (3) ◽  
pp. 697-700 ◽  
Author(s):  
D. B. Jan ◽  
Q. X. Jia ◽  
M. E. Hawley ◽  
G. W. Browne ◽  
C. J. Wetteland ◽  
...  

The formation of superconducting YBa2Cu3O7–x (Y123) by in situ pulsed laser deposition from a stoichiometric Y123 target typically requires an oxygen-ambient environment (P ˜ 100–300-mtorr O2) and appropriate substrate temperature during deposition. We have found that pulsed laser deposition from a Y123 target in vacuo onto a (001) LaAlO3 substrate favors the formation of Y2O3. We observed that the Y2O3 (001) films yield three-dimensional nanoscale morphologies that are markedly different from the planar growth surface of conventional superconducting c-axis Y123 films and Y2O3 films formed from the pulsed laser ablation of a Y2O3 target.


2006 ◽  
Vol 200 (12-13) ◽  
pp. 4027-4031 ◽  
Author(s):  
D.M. Zhang ◽  
L. Guan ◽  
Z.H. Li ◽  
G.J. Pan ◽  
H.Z. Sun ◽  
...  

MRS Bulletin ◽  
1992 ◽  
Vol 17 (2) ◽  
pp. 26-29 ◽  
Author(s):  
Graham K. Hubler

Research on materials grown by pulsed laser deposition, or PLD, has experienced phenomenal growth since late 1987 when T. Venkatesan (one of the authors for this issue) and co-workers pointed out that extreme nonequilibrium conditions created by pulsed laser melting of YBaCuO allowed in-situ preparation of thin films of this high transition temperature (Tc) superconducting material. Since then, PLD has emerged as the primary means for high throughput deposition of high-quality superconducting thin films for research and devices. This probably came as no surprise to J.T. Cheung (another of this issue's authors), who performed original research in this area and tirelessly labored during the 1980s to convince a skeptical audience of the advantages of PLD.Along with the success of PLD in the arena of high-temperature superconductivity, however, is the explosion of activity in the deposition of many other materials, made possible by the unique features of pulsed laser deposition, materials previously not amenable to in-situ thin film growth. Creative minds reasoned that since PLD can deposit a demanding, complex material such as the perovskite structure Y1Ba2Cu3O7-δ, why not other perovskites or multicomponent oxide materials? It also turns out that the range of properties of multicomponent oxides is virtually limitless. They can be metallic, insulating, semiconducting, biocompatable, superconducting, ferroelectric, piezoelectric, and so on. One is not limited to the properties of elements or binary compounds on which the electronics and microelectronics industries are based. Indeed, in a recent review of hybrid ferromagnetic- semiconductor structures, G. Prinz states, “… there has been little work devoted to incorporating magnetic materials into planar integrated electronic (or photonic) circuitry there are potential applications that have no analog in vacuum electronics but that remain unrealized, awaiting the development of appropriate materials and processing procedures.” In pulsed laser deposition, we may well have in hand the “appropriate processing procedure” to deposit sequential epitaxial layers of high quality materials that possess profoundly different properties.


2003 ◽  
Vol 788 ◽  
Author(s):  
Xinyu Wang ◽  
Sergey Yarmolenko ◽  
Dhananjay Kumar ◽  
Zhigang Xu ◽  
Jagannathan Sankar

ABSTRACTPulsed laser deposition (PLD) technique was used to grow alumina (Al2O3) thin films on (100) silicon substrate under different deposition conditions. The relationship between Al2O3thin film thickness, hardness, elastic modulus, surface morphology and PLD parameters such as laser energy and substrate temperature was investigated. The Film thickness was found to increase with an increase in laser energy and to decrease with an increase in substrate temperature. The film hardness and elastic modulus increases as substrate temperature increases. We have also shown that films are amorphous at lower substrate temperatures and transform to mixture of amorphous and crystalline phases. The ratio of amorphous to crystalline phases decreases with increase in temperature. The surfaces of Al2O3film grown using PLD was found very smooth with least root square roughness less than 2 nm.


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