FIB preparation of cross-sectional polymer thin film TEM samples

Structural appraisal of thin film magnetic media is very important because their magnetic characters such as magnetic hysteresis and recording behaviors are drastically altered by the grain structure of the film. However, in general, the surface of thin film magnetic media of magnetic recording disk which is process completed is protected by several-nm thick sputtered carbon. Therefore, high-resolution observation of a cross-sectional plane of a disk is strongly required to see the fine structure of the thin film magnetic media. Additionally, observation of the top protection film is also very important in this field.Recently, several different process-completed magnetic disks were examined with a UHR-SEM, the JEOL JSM 890, which consisted of a field emission gun and a high-performance immerse lens. The disks were cut into approximately 10-mm squares, the bottom of these pieces were carved into more than half of the total thickness of the disks, and they were bent. There were many cracks on the bent disks. When these disks were observed with the UHR-SEM, it was very difficult to observe the fine structure of thin film magnetic media which appeared on the cracks, because of a very heavy contamination on the observing area.

Download Full-text

Effect of Illumination on Organic Polymer Thin-Film Transistors

MRS Proceedings ◽

10.1557/proc-771-l10.17 ◽

2003 ◽

Vol 771 ◽

Cited By ~ 3

Author(s):

Michael C. Hamilton ◽

Sandrine Martin ◽

Jerzy Kanicki

Keyword(s):

Thin Film ◽

Thin Film Transistors ◽

Drain Current ◽

Charge Carriers ◽

Electrical Performance ◽

Organic Polymer ◽

Light Illumination ◽

Polymer Thin Film ◽

Channel Region ◽

White Light Illumination

AbstractWe have investigated the effects of white-light illumination on the electrical performance of organic polymer thin-film transistors (OP-TFTs). The OFF-state drain current is significantly increased, while the drain current in the strong accumulation regime is relatively unaffected. At the same time, the threshold voltage is decreased and the subthreshold slope is increased, while the field-effect mobility of the charge carriers is not affected. The observed effects are explained in terms of the photogeneration of free charge carriers in the channel region due to the absorbed photons.

Download Full-text

Conducting polymer thin film for optoelectronic devices applications

Polymers for Advanced Technologies ◽

10.1002/pat.5290 ◽

2021 ◽

Author(s):

Mohamed H. Abdel‐Aziz ◽

Mohammed Zwawi ◽

Ahmed F. Al‐Hossainy ◽

Mohamed Sh. Zoromba

Keyword(s):

Thin Film ◽

Conducting Polymer ◽

Optoelectronic Devices ◽

Polymer Thin Film

Download Full-text

Bilayer PMMA antireflective coatings via microphase separation and MAPLE

Journal of Polymer Engineering ◽

10.1515/polyeng-2020-0198 ◽

2020 ◽

Vol 41 (2) ◽

pp. 164-173

Author(s):

Yunlong Guo ◽

Shuzhen Ren

Keyword(s):

Microphase Separation ◽

Incident Light ◽

Visible Range ◽

Laser Evaporation ◽

Antireflective Coatings ◽

Porous Network ◽

Cross Sectional ◽

Polymer Thin Film ◽

Deposition Parameters ◽

Surface Morphologies

Abstract A poly(methyl methacrylate) (PMMA) bilayer antireflective coating (ARC) is designed based on polymeric microphase separation and matrix-assisted pulsed laser evaporation (MAPLE). The spin-coated layer shows subwavelength porous network structures, after phase separation via annealing and removal of the polystyrene (PS) phase, while the MAPLE deposited surface layer exhibits a biomimic moth-eye structure on glass to trap the incident light. The elaborate spin coated structure can be controlled flexibly by changing the ratio of mixture, annealing time and temperature, and the moth-eye structure can also be tuned by deposition parameters. The transmittance of the ARC presents a maximum of 95.64% and an average of 94.81% in visible range. The moth-eye structure on glass substrate formed by nanoglobules makes positive contributions to the improvement of transmittance according to UV–Vis result and simulation. The wetting motion of PMMA globules is observed as well by the comparison of AFM surface morphologies and cross-sectional profiles of globules on glass and polymer thin film. This work is a novel attempt to fabricate bilayer ARC with two different structures by a single polymeric material and will provide new route for fabrication of multilayer ARCs.

Download Full-text

Optimizing the Properties of La0.8Sr0.2CrO3 Thin Films through Post-Annealing for High-Temperature Sensing

Nanomaterials ◽

10.3390/nano11071802 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1802

Author(s):

Dan Liu ◽

Peng Shi ◽

Yantao Liu ◽

Yijun Zhang ◽

Bian Tian ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Annealing Temperature ◽

Rf Sputtering ◽

Maximum Size ◽

Cross Sectional ◽

Post Annealing ◽

Maximum Conductivity ◽

Different Temperatures ◽

Post Annealing Temperature

La0.8Sr0.2CrO3 (0.2LSCO) thin films were prepared via the RF sputtering method to fabricate thin-film thermocouples (TFTCs), and post-annealing processes were employed to optimize their properties to sense high temperatures. The XRD patterns of the 0.2LSCO thin films showed a pure phase, and their crystallinities increased with the post-annealing temperature from 800 °C to 1000 °C, while some impurity phases of Cr2O3 and SrCr2O7 were observed above 1000 °C. The surface images indicated that the grain size increased first and then decreased, and the maximum size was 0.71 μm at 1100 °C. The cross-sectional images showed that the thickness of the 0.2LSCO thin films decreased significantly above 1000 °C, which was mainly due to the evaporation of Sr2+ and Cr3+. At the same time, the maximum conductivity was achieved for the film annealed at 1000 °C, which was 6.25 × 10−2 S/cm. When the thin films post-annealed at different temperatures were coupled with Pt reference electrodes to form TFTCs, the trend of output voltage to first increase and then decrease was observed, and the maximum average Seebeck coefficient of 167.8 µV/°C was obtained for the 0.2LSCO thin film post-annealed at 1100 °C. Through post-annealing optimization, the best post-annealing temperature was 1000 °C, which made the 0.2LSCO thin film more stable to monitor the temperatures of turbine engines for a long period of time.

Download Full-text

A Theoretical Study on an Elastic Polymer Thin Film-Based Capacitive Wind-Pressure Sensor

Polymers ◽

10.3390/polym12092133 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2133

Author(s):

Xue Li ◽

Jun-Yi Sun ◽

Bin-Bin Shi ◽

Zhi-Hang Zhao ◽

Xiao-Ting He

Keyword(s):

Thin Film ◽

Closed Form ◽

Pressure Sensor ◽

Closed Form Solution ◽

Form Solution ◽

Wind Pressure ◽

Polymer Thin Film ◽

Movable Electrode ◽

Elastic Polymer ◽

Electrode Plate

This study is devoted to the design of an elastic polymer thin film-based capacitive wind-pressure sensor to meet the anticipated use for real-time monitoring of structural wind pressure in civil engineering. This sensor is composed of four basic units: lateral elastic deflection unit of a wind-driven circular polymer thin film, parallel plate capacitor with a movable circular electrode plate, spring-driven return unit of the movable electrode plate, and dielectric materials between electrode plates. The capacitance of the capacitor varies with the parallel move of the movable electrode plate which is first driven by the lateral elastic deflection of the wind-driven film and then is, after the wind pressure is reduced or eliminated, returned quickly by the drive springs. The closed-form solution for the contact problem between the wind-driven thin film and the spring-driven movable electrode plate is presented, and its reliability is proved by the experiment conducted. The numerical examples conducted show that it is workable that by using the numerical calibration based on the presented closed-form solution the proposed sensor is designed into a nonlinear sensor with larger pressure-monitoring range and faster response speed than the linear sensor usually based on experimental calibration.

Download Full-text