Domain structure of epitaxial PbTio3 thin films: Effects of substrate selection and film thickness

A study of epitaxial Bi4Ti3O12 thin films with a pre-deposited 4 nm Ba0.4Sr0.6TiO3 sublay-er on (001) MgO substrates has been performed. In the obtained heterostructures, the rotation of the Bi4Ti3O12 film unit cells by an angle of 45° relative to the MgO substrate unit cell in the inter-face plane has been observed. The Bi4Ti3O12 films contain unit cell deformations depending on the thickness of the film and the sign of the deformation changes at a thickness of ~40 nm. The switchable in-plane spontaneous polarization of Bi4Ti3O12 film at the 180° domain structure oc-curs at a film thickness of 10 nm and increases with a thickness up to 54 µC/cm2. The study of the dielectric characteristics of the films confirmed the existence of properties anisotropy in the interface plane and the effect of deformation of the unit cell on the properties of heterostruc-tures.

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Domains and domain nucleation in magnetron-sputtered CoCr thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151064 ◽

1993 ◽

Vol 51 ◽

pp. 1046-1047

Author(s):

B. G. Demczyk

Keyword(s):

Thin Films ◽

Domain Structure ◽

Magnetic Domain ◽

Domain Size ◽

Film Plane ◽

Magnetic Domain Structure ◽

Perpendicular Magnetization ◽

Columnar Grains ◽

Reversal Mechanism ◽

Lorentz Transmission Electron Microscopy

CoCr thin films have been of interest for a number of years due to their strong perpendicular anisotropy, favoring magnetization normal to the film plane. The microstructure and magnetic properties of CoCr films prepared by both rf and magnetron sputtering have been examined in detail. By comparison, however, relatively few systematic studies of the magnetic domain structure and its relation to the observed film microstructure have been reported. In addition, questions still remain as to the operative magnetization reversal mechanism in different film thickness regimes. In this work, the magnetic domain structure in magnetron sputtered Co-22 at.%Cr thin films of known microstructure were examined by Lorentz transmission electron microscopy. Additionally, domain nucleation studies were undertaken via in-situ heating experiments.It was found that the 50 nm thick films, which are comprised of columnar grains, display a “dot” type domain configuration (Figure 1d), characteristic of a perpendicular magnetization. The domain size was found to be on the order of a few structural columns in diameter.

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Giant Anisotropy of Conductivity in Hydrogenated Nanocrystalline Silicon Thin Films

MRS Proceedings ◽

10.1557/proc-536-275 ◽

1998 ◽

Vol 536 ◽

Author(s):

A. B. Pevtsov ◽

N. A. Feoktistov ◽

V. G. Golubev

Keyword(s):

Thin Films ◽

Film Thickness ◽

Percolation Theory ◽

Nanocrystalline Silicon ◽

Spatial Light Modulators ◽

Light Emitting ◽

Light Modulators ◽

Silicon Thin Films ◽

Longitudinal Conductivity ◽

Transverse Conductivity

AbstractThin (<1000 Å) hydrogenated nanocrystalline silicon films are widely used in solar cells, light emitting diodes, and spatial light modulators. In this work the conductivity of doped and undoped amorphous-nanocrystalline silicon thin films is studied as a function of film thickness: a giant anisotropy of conductivity is established. The longitudinal conductivity decreases dramatically (by a factor of 109 − 1010) as the layer thickness is reduced from 1500 Å to 200 Å, while the transverse conductivity remains close to that of a doped a- Si:H. The data obtained are interpreted in terms of the percolation theory.

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Optical Constant and Conformality Analysis of SiO2 Thin Films Deposited on Linear Array Microstructure Substrate by PECVD

Coatings ◽

10.3390/coatings11050510 ◽

2021 ◽

Vol 11 (5) ◽

pp. 510

Author(s):

Yongqiang Pan ◽

Huan Liu ◽

Zhuoman Wang ◽

Jinmei Jia ◽

Jijie Zhao

Keyword(s):

Thin Films ◽

Film Thickness ◽

Deposition Rate ◽

Optical Constant ◽

Photoelectron Spectroscopy ◽

Linear Array ◽

Chemical Vapor ◽

Rf Plasma ◽

X Ray ◽

Sio2 Thin Film

SiO2 thin films are deposited by radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) technique using SiH4 and N2O as precursor gases. The stoichiometry of SiO2 thin films is determined by the X-ray photoelectron spectroscopy (XPS), and the optical constant n and k are obtained by using variable angle spectroscopic ellipsometer (VASE) in the spectral range 380–1600 nm. The refractive index and extinction coefficient of the deposited SiO2 thin films at 500 nm are 1.464 and 0.0069, respectively. The deposition rate of SiO2 thin films is controlled by changing the reaction pressure. The effects of deposition rate, film thickness, and microstructure size on the conformality of SiO2 thin films are studied. The conformality of SiO2 thin films increases from 0.68 to 0.91, with the increase of deposition rate of the SiO2 thin film from 20.84 to 41.92 nm/min. The conformality of SiO2 thin films decreases with the increase of film thickness, and the higher the step height, the smaller the conformality of SiO2 thin films.

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Emergence and Evolution of Crystallization in TiO2 Thin Films: A Structural and Morphological Study

Nanomaterials ◽

10.3390/nano11061409 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1409

Author(s):

Ofelia Durante ◽

Cinzia Di Giorgio ◽

Veronica Granata ◽

Joshua Neilson ◽

Rosalba Fittipaldi ◽

...

Keyword(s):

Thin Films ◽

Film Thickness ◽

Transition Metal Oxides ◽

Annealing Temperature ◽

Morphological Properties ◽

Degree Of Crystallinity ◽

Tio2 Thin Films ◽

Force Microscopy ◽

Heat Treated ◽

Complementary Techniques

Among all transition metal oxides, titanium dioxide (TiO2) is one of the most intensively investigated materials due to its large range of applications, both in the amorphous and crystalline forms. We have produced amorphous TiO2 thin films by means of room temperature ion-plasma assisted e-beam deposition, and we have heat-treated the samples to study the onset of crystallization. Herein, we have detailed the earliest stage and the evolution of crystallization, as a function of both the annealing temperature, in the range 250–1000 °C, and the TiO2 thickness, varying between 5 and 200 nm. We have explored the structural and morphological properties of the as grown and heat-treated samples with Atomic Force Microscopy, Scanning Electron Microscopy, X-ray Diffractometry, and Raman spectroscopy. We have observed an increasing crystallization onset temperature as the film thickness is reduced, as well as remarkable differences in the crystallization evolution, depending on the film thickness. Moreover, we have shown a strong cross-talking among the complementary techniques used displaying that also surface imaging can provide distinctive information on material crystallization. Finally, we have also explored the phonon lifetime as a function of the TiO2 thickness and annealing temperature, both ultimately affecting the degree of crystallinity.

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Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽

10.3390/coatings11010023 ◽

2020 ◽

Vol 11 (1) ◽

pp. 23

Author(s):

Weiguang Zhang ◽

Jijun Li ◽

Yongming Xing ◽

Xiaomeng Nie ◽

Fengchao Lang ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Grain Size ◽

Integrated Circuits ◽

Film Thickness ◽

Depth Range ◽

Micro Electro Mechanical Systems ◽

Si Substrates ◽

Sio2 Thin Film ◽

Average Grain Size

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

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