Search Results for magnetic force microscopy

Microstructural analysis of specialized types of magnetic materials is centered on the examination of optical, electron, and scanning probe metallographic techniques unique to magnetic materials. This article provides a comprehensive overview of magnetic materials, their characteristics and sample preparation procedures. It reviews the methods pertaining to the microstructural examination of bulk magnetic materials, including microscopy techniques specified to magnetic materials characterization, with specific examples. The techniques used in the study of magnetic domain structures (microstructure) include the magneto-optical Kerr method, the Faraday method, the Bitter technique, scanning electron microscopy (magnetic contrast Types I and II), scanning electron microscopy with polarization analysis, Lorentz transmission electron microscopy, and magnetic force microscopy. The article also illustrates the microstructure of different types of soft magnetic material and permanent magnets.

This article focuses on laboratory atomic force microscopes (AFMs) used in ambient air and liquid environments. It begins with a discussion on the origin of AFM and development trends occurring in AFM. This is followed by a section on the general principles of AFM and a comprehensive list of AFM scanning modes. There is a brief description of how each mode works and what types of applications can be made with each mode. Some of the processes involved in preparation of samples (bulk materials and those placed on a substrate) scanned in an AFM are then presented. The article provides information on the factors applicable to the accuracy and precision of AFM measurements. It ends by discussing the applications for AFMs in the fields of science, technology, and engineering.

This article provides an overview of scanning probe microscopes (scanning tunneling microscope and atomic force microscope (AFM)), covering the various operating modes and probes used in these instruments and providing information on AFM instrumentation, applications, and analyses.

This article describes the test techniques that are available for monitoring crack initiation and crack growth and for obtaining information on fatigue damage in test specimens. These techniques include optical methods, the compliance method, electric potential measurement, and gel electrode imaging methods. The article discusses the magnetic techniques that are primarily used as inspection techniques for detecting fatigue cracks in structural components. It details the principles and operation procedures of the liquid penetrant methods, positron annihilation techniques, acoustic emission techniques, ultrasonic methods, eddy current techniques, infrared techniques, exoelectron methods, and gamma radiography. The article explains the microscopy methods used to determine fatigue crack initiation and propagation. These include electron microscopy, scanning tunneling microscopy, atomic force microscopy, and scanning acoustic microscopy. The article also reviews the X-ray diffraction technique used for determining the compositional changes, strain changes, and residual stress evaluation during the fatigue process.

This article is an overview of the division Surface Analysis of this volume. The division covers various developed surface-analysis techniques, such as scanning probe and atomic force microscopy. The division focuses on the analysis of surface layers that are less than 100 nm. A quick reference summary of surface-analysis methods is presented in this article.

This article describes the fundamental theory of magnetic pulse welding (MPW). It reviews the equipment used for MPW, namely, work coil, capacitor bank, high-voltage power supply, high-voltage switches, and field shapers. The article discusses the MPW process and explains the critical parameters needed to obtain acceptable welds. Applications and safety guidelines of the MPW are also presented.

Quality control of cemented carbides includes the evaluation of physical and chemical properties of constituent raw material powders, powder blends/formulations, green compacts, and fully dense finished product. This article provides a summary of the underlying principles and size ranges for the American Society for Testing and Materials (ASTM) standard methods of particle sizing and distribution. It presents the methods used to analyze the chemical composition of cemented carbide materials in a tabular form. The article also presents information on microstructural evaluation and physical and mechanical property evaluation of cemented carbides.

This article introduces various analytical techniques commonly used in the characterization of organic solids and liquids and discusses the challenges in performing the analysis, with examples. Some general advice in approaching a material analysis is also provided.

This article briefly discusses popular techniques for metals characterization. It begins with a description of the most common techniques for determining chemical composition of metals, namely X-ray fluorescence, optical emission spectroscopy, inductively coupled plasma optical emission spectroscopy, high-temperature combustion, and inert gas fusion. This is followed by a section on techniques for determining the atomic structure of crystals, namely X-ray diffraction, neutron diffraction, and electron diffraction. Types of electron microscopies most commonly used for microstructural analysis of metals, such as scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy, are then reviewed. The article contains tables listing analytical methods used for characterization of metals and alloys and surface analysis techniques. It ends by discussing the objective of metallography.

Grain boundaries are interfaces between crystallites of the same phase but different crystallographic orientation. They can be characterized as being low angle or high angle. This article discusses the measurements of grain-boundary energy with a brief summary of different schemes for measuring grain-boundary surface tension. The atomistic simulations of grain-boundary energy, measurement of grain-boundary migration and the techniques used to monitor grain-boundary migration are reviewed. Several considerations and effects influencing the computation of grain-boundary mobility are also discussed.

This article reviews nondestructive testing (NDT) and inspection techniques, namely liquid penetrant, magnetic particle, ultrasonics, X-ray, eddy current, visual and radiography that are commonly used to detect and evaluate flaws or leaks in an engineering system. This article compares the merits and limitations of these techniques and describes the various uses of NDT, including leak detection, metrology, structure or microstructure characterization, stress-strain response determination, and rapid identification of metals and alloys.

Superconductivity has been found in a wide range of materials, including pure metals, alloys, compounds, oxides, and organic materials. Providing information on the basic principles, this article discusses the theoretical background, types of superconductors, and critical parameters of superconductivity. It discusses the magnetic properties of selected superconductors and types of stabilization, including cryogenic stability, adiabatic stability, and dynamic stability. The article also focuses on alternating current losses in superconductors, including hysteresis loss, penetration loss, eddy current loss, and radio frequency loss. Furthermore, the article describes the flux pinning phenomenon and Josephson effects.