Growth of Manganese Oxide Thin Films by Pulsed Laser Deposition
Growth of Manganese Oxide Thin Films by Pulsed Laser Deposition

Author: Elissar Suheil Majdalani

Publisher:

Published: 2006

Total Pages: 182

ISBN-13:

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A KrF excimer laser is used to ablate a pure MnO target to grow manganese oxide thin films on Si (111) substrates. The effect of oxygen pressure and substrate t emperature on the various film properties were investigated. Grazing incidence X -ray diffraction (GIXRD) is employed to determine the crystalline structure, whe reas Atomic Force Microscopy (AFM) is used to determine the surface roughness. C hemical bonding and the elemental composition were studied using Fourier Transfo rm Infrared Spectroscopy (FTIR) and Rutherford Backscattering Spectroscopy (RBS) . Two manganese oxide phases were obtained, namely Manganesetrioxide (Mn2O3) and M anganesetetraoxide (Mn3O4). GIXRD analysis indicates that the increase in substr ate temperature at a constant oxygen pressure leads to a change in the phase com position from Manganesetrioxide (Mn2O3) to Manganesetetraoxide (Mn3O4). FTIR stu dies support this result. The FWHM measurements reveal that the films become mor e crystalline at higher temperatures. Moreover, AFM measurements show that the f ilm roughness increases with the increase in temperature due to the fact that su rface atoms mobility is enhanced at higher temperatures. At constant temperature ; however, it was shown by both GIXRD and FTIR that varying the oxygen pressure does not affect the composition and crystallinity of the films. On the other han d, it has a considerable effect on the atomic ration of oxygen-to manganese obta ined by RBS.

Phase Control of Manganese Dioxide Thin Films by Plasma Assisted Laser Ablation
Phase Control of Manganese Dioxide Thin Films by Plasma Assisted Laser Ablation

Author: Maya Nadim Abi Akl

Publisher:

Published: 2009

Total Pages: 192

ISBN-13:

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The aim of this work is to investigate the growth of manganese dioxide thin film s by conventional Pulsed Laser Deposition (PLD) and Remote Plasma Assisted-PLD (RPA-PLD) in order to assess the role of plasma activation on promoting high oxid ation state of manganese and to improve the structural and morphological properties of the grown layers. For this purpose, films were grown on Si (100) substrate by K rF excimer laser ablation of a MnO target. The effects of substrate temperature, oxygen pressure and plasma activation on composition, crystallinity, structure, surface morphology, and growth rate were studied using Grazing Incidence X-Ray Diffraction (GIXRD), Fourier Transform Infra-Red Spectroscopy (FTIR), Raman Spec troscopy, Atomic Force Microscopy (AFM) and Surface Profilometry. The optimal temperature to grow manganese dioxide films in terms of crystalline quality was found to be 500 degreesC. Crystallinity appears to deteriorate at lo wer deposition temperature, while at higher temperature, the Dimanganese trioxid e phase is stabilized. Deposition at high oxygen pressures (250 and 500 mTorr) r esulted in the formation of stoichiometric manganese dioxide films, but the unde rlying structure of the layers was identified as gamma-manganese dioxide, consis ting of an irregular intergrowth of R- and beta-manganese dioxide which caused b roadening of XRD peaks and IR bands. Plasma activation of the process leads to l ittle improvement of film quality in this range of pressure. Alternatively, oper ation at low pressure values (1 to 50 mTorr) with plasma assistance was examined . While deposition in oxygen ambient in this pressure range led to the formation of di-manganese trioxide and Hausmanite, plasma activation induced a shift in t he Mn-O phase diagram allowing the synthesis of manganese dioxide, even at such low pressures. The corresponding films consisted of pure and highly crystalline beta-manganese dioxide with extremely smooth sur faces of roughness values as low as 0.5 nm. Such results highlight the necessity of using RPAPLD when aiming to grow high quality oxide films such as manganese dioxide.

Strain Controlled Functionalities in Lightly Doped Manganite Perovskite Epitaxial Thin Films Grown by Pulsed Laser Deposition
Strain Controlled Functionalities in Lightly Doped Manganite Perovskite Epitaxial Thin Films Grown by Pulsed Laser Deposition

Author: Richard Teboh Mbatang

Publisher:

Published: 2018

Total Pages: 188

ISBN-13:

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Functional Oxides have been widely studied in the last decades because of their fascinating properties as ferromagnetism, ferroelectricity, superconductivity and multiferroicity. The widely studied complex oxides are the perovskite and the hexagonal oxides. Intriguing phenomena have been observed in epitaxial thin films of manganite perovskites, which greatly differed from those of bulk material. Some of the interesting properties of lightly doped manganite oxide thin films, especially La0.9Sr0.1MnO3 thin films, are an enhanced magnetoresistance (MR) and temperature coefficient of resistance (TCR). The physical properties of these films are related to the effects that occur at the interface. Some of these interfacial effects includes defect formation, charge transfer, exchange coupling, strain, interfacial reconstruction and cation intermixing. The fast development of new characterization techniques have made the study of interfacial effects easy. Fabrication techniques such as Pulsed Laser Deposition (PLD) have been employed to produce interfaces with great atomic precision. Selecting materials with the right lattice mismatch and optimization of the growth conditions as laser repetition rate, temperature, oxygen pressure, substrate-target distance and laser energy are crucial in growth of epitaxial thin films for functional device application. In addition to these, selecting the right proposition of the various phase is important in achieving the right microstructure for composite films. The main focus of this dissertation is to investigate the relationship between structure and magneto-transport properties in lightly doped manganite perovskite thin films with the concentration on 10% strontium doped lathanum manganese oxide, La0.9Sr0.1MnO3 (LSMO) grown by Pulsed Laser Deposition (PLD). We grew films of different thicknesses (15 nm, 30 nm, 75 nm) and on different substrates ((001) LaAlO3 (LAO, (001) SrLaGaO4 (LSGO), (110), GdScO3 (DSO) and (110) GaScO3). We found that thinner films show highly enhanced magnetic and transport properties while thicker films exhibit low transport and magnetic properties due to strain relaxation. We also observed that compressive strain enhanced magnetic (saturation magnetization, Curie temperature (Tc)) and transport properties (metal-insulating transition (MIT), magnetoresistance (MR), temperature coefficient of resistance (TCR)). The enhancement of magnetic and transport properties were attributed to the suppression of Jahn-Teller distortion, electron-phonon coupling and the enhancement of double exchange coupling. In summary, strain can be used to tune the physical properties of expitaxial thin films for technological applications.

Growth and Characterization of Ferromagnetic LCMO and Ferroelectric PZT Thin Films
Growth and Characterization of Ferromagnetic LCMO and Ferroelectric PZT Thin Films

Author: Walter Gilmore

Publisher:

Published: 2002

Total Pages: 246

ISBN-13:

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Addresses the phenomena of colossal magnetoresistance (CMR) and magnetic properties associated with the incorporation of ferromagnetic (FM) lanthanum calcium manganese oxide (LCMO) (in thin film and nanoparticle form) into Si (silicon)-based systems. Discusses the growth FM lanthanum calcium manganese oxide (LCMO) thin films by pulsed laser deposition (PLD) on Si substrates by using a high conducting barrier layer of titanium nitrogen (TiN). Uses magnesium oxygen (MgO) and strontium titanium ozone (SrTiO3) films as intermediate layers between LCMO and TiN layers in order to prevent interfacial interactions with oxygen and to achieve epitaxial growth of LCMO films. Investigates the growth, characterization, and electrical properties of ferroelectric (FE) lead zirconium titanate (PZT) thin films on Si-based systems. Embeds well-separated non-interacting LCMO nanoparticles in an insulating medium using PLD.

Pulsed Laser Deposition of Thin Films
Pulsed Laser Deposition of Thin Films

Author: Robert Eason

Publisher: John Wiley & Sons

Published: 2007-12-14

Total Pages: 754

ISBN-13: 0470052112

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Edited by major contributors to the field, this text summarizes current or newly emerging pulsed laser deposition application areas. It spans the field of optical devices, electronic materials, sensors and actuators, biomaterials, and organic polymers. Every scientist, technologist and development engineer who has a need to grow and pattern, to apply and use thin film materials will regard this book as a must-have resource.

Growth of Semiconductor Thin Films by Pulsed Laser Deposition
Growth of Semiconductor Thin Films by Pulsed Laser Deposition

Author: Yilu Li

Publisher:

Published: 2016

Total Pages: 97

ISBN-13:

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Pulsed ultraviolet light from a XeF excimer laser was used to grow thin films of zinc oxide and tin dioxide on (111) p-type silicon wafers within a versatile high vacuum laser deposition system. This pulsed laser deposition system was self-designed and self-built. Parameters such as pressure, target temperature, and distance from the target to the substrate can be adjusted in the system. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction spectroscopy, Raman spectroscopy and ellipsometry were used to analyze the structures and properties of ZnO and SnO2 thin films. The critical temperature required to fabricate a crystalline ZnO thin film by pulsed laser deposition was found and has been confirmed. For the SnO2 thin film, the critical temperature required to generate a crystalline structure could not be found because of the temperature limit of the substrate heater used in the experiment. In SnO2 thin films, thermal annealing has been used to convert into crystalline structure with (110), (101) and (211) orientations. After fabricating the amorphous SnO2 thin films, they were put into an oven with specific temperatures to anneal them. The minimum annealing temperature range was found for converting the amorphous SnO2 thin films into SnO2 thin films with a crystalline structure. Thermal annealing has also been applied to some amorphous ZnO thin films which were fabricated under the critical temperature required to produce crystalline ZnO thin films. The minimum annealing temperature range for amorphous ZnO thin films was found and only one orientation (002) shown after annealing. Laser annealing technology has also been applied for converting both amorphous ZnO and SnO2 thin films, and results show that this method was not well suited for this attempt. ZnO thin films and SnO2 thin films with a crystalline structure have inportant widely used in industry, for example, application in devices such as solar cells and UV or blue-light-emitting devices. The aim of this research is to help improving the manufacturing process of ZnO and SnO2 thin films.