Characterization, when used in materials science, refers to the broad and general process by which a material's structure and properties are probed and measured. It is a fundamental process in the field of materials science, without which no scientific understanding of engineering materials could be ascertained. The scope of the term often differs; some definitions limit the term's use to techniques which study the microscopic structure and properties of materials, while others use the term to refer to any materials analysis process including macroscopic techniques such as mechanical testing, thermal analysis and density calculation. The scale of the structures observed in materials characterization ranges from angstroms, such as in the imaging of individual atoms and chemical bonds, up to centimeters, such as in the imaging of coarse grain structures in metals. While many characterization techniques have been practiced for centuries, such as basic optical microscopy, new techniques and methodologies are constantly emerging. In particular the advent of the

electron microscope An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a hi ...

and secondary ion mass spectrometry in the 20th century has revolutionized the field, allowing the imaging and analysis of structures and compositions on much smaller scales than was previously possible, leading to a huge increase in the level of understanding as to why different materials show different properties and behaviors.Mathys, Daniel, Zentrum für Mikroskopie,

University of Basel The University of Basel (Latin: ''Universitas Basiliensis'', German: ''Universität Basel'') is a university in Basel, Switzerland. Founded on 4 April 1460, it is Switzerland's oldest university and among the world's oldest surviving universit ...

: ''Die Entwicklung der Elektronenmikroskopie vom Bild über die Analyse zum Nanolabor'', p. 8 More recently,

atomic force microscopy Atomic force microscopy (AFM) or scanning force microscopy (SFM) is a very-high-resolution type of scanning probe microscopy (SPM), with demonstrated resolution on the order of fractions of a nanometer, more than 1000 times better than the op ...

has further increased the maximum possible resolution for analysis of certain samples in the last 30 years.

Microscopy

Microscopy Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of micr ...

is a category of characterization techniques which probe and map the surface and sub-surface structure of a material. These techniques can use

photon A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they always ...

electron The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no kn ...

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

s or physical cantilever probes to gather data about a sample's structure on a range of length scales. Some common examples of microscopy techniques include: * Optical microscopy * Scanning electron microscopy (SEM) *

Transmission electron microscopy Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a g ...

(TEM) * Field ion microscopy (FIM) *

Scanning probe microscopy Scan may refer to: Acronyms * Schedules for Clinical Assessment in Neuropsychiatry (SCAN), a psychiatric diagnostic tool developed by WHO * Shared Check Authorization Network (SCAN), a database of bad check writers and collection agency for bad ...

(SPM) **

Atomic force microscopy Atomic force microscopy (AFM) or scanning force microscopy (SFM) is a very-high-resolution type of scanning probe microscopy (SPM), with demonstrated resolution on the order of fractions of a nanometer, more than 1000 times better than the op ...

(AFM) ** Scanning tunneling microscopy (STM) * X-ray diffraction topography (XRT)

Spectroscopy

Spectroscopy Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...

is a category of characterization techniques which use a range of principles to reveal the chemical composition, composition variation, crystal structure and photoelectric properties of materials. Some common examples of spectroscopy techniques include:

Optical radiation

* Ultraviolet-visible spectroscopy (UV-vis) *

Fourier transform infrared spectroscopy Fourier-transform infrared spectroscopy (FTIR) is a technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas. An FTIR spectrometer simultaneously collects high-resolution spectral data over a wide spectr ...

(FTIR) *

Thermoluminescence Thermoluminescence is a form of luminescence that is exhibited by certain crystalline materials, such as some minerals, when previously absorbed energy from electromagnetic radiation or other ionizing radiation is re-emitted as light upon he ...

(TL) *

Photoluminescence Photoluminescence (abbreviated as PL) is light emission from any form of matter after the absorption of photons (electromagnetic radiation). It is one of many forms of luminescence (light emission) and is initiated by photoexcitation (i.e. photon ...

(PL)

X-ray

X-ray diffraction X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles ...

(XRD) * Small-angle X-ray scattering (SAXS) * Energy-dispersive X-ray spectroscopy (EDX, EDS) * Wavelength dispersive X-ray spectroscopy (WDX, WDS) * Electron energy loss spectroscopy (EELS) * X-ray photoelectron spectroscopy (XPS) *

Auger electron spectroscopy file:HD.6C.037 (11856519893).jpg, A Hanford Site, Hanford scientist uses an Auger electron spectrometer to determine the elemental composition of surfaces. Auger electron spectroscopy (AES; pronounced in French) is a common analytical technique us ...

(AES) *

X-ray photon correlation spectroscopy X-ray photon correlation spectroscopy (XPCS) in physics and chemistry, is a novel technique that exploits a coherent X-ray synchrotron beam to measure the dynamics of a sample. By recording how coherent speckle fluctuations in time, one can meas ...

(XPCS)

Mass spectrometry

*Modes of mass spectrometry: **

Electron ionization Electron ionization (EI, formerly known as electron impact ionization and electron bombardment ionization) is an ionization method in which energetic electrons interact with solid or gas phase atoms or molecules to produce ions. EI was one of th ...

(EI) ** Thermal ionization mass spectrometry (TI-MS) **

MALDI-TOF In mass spectrometry, matrix-assisted laser desorption/ionization (MALDI) is an ionization technique that uses a laser energy absorbing matrix to create ions from large molecules with minimal fragmentation. It has been applied to the analysis of b ...

* Secondary ion mass spectrometry (SIMS)

Nuclear spectroscopy

* Nuclear magnetic resonance spectroscopy (NMR) * Mössbauer spectroscopy (MBS) * Perturbed angular correlation (PAC)

Other

Photon correlation spectroscopy Dynamic light scattering (DLS) is a technique in physics that can be used to determine the size distribution profile of small particles in suspension or polymers in solution. In the scope of DLS, temporal fluctuations are usually analyzed using t ...

/ Dynamic light scattering (DLS) *

Terahertz spectroscopy Terahertz spectroscopy detects and controls properties of matter with electromagnetic fields that are in the frequency range between a few hundred gigahertz and several terahertz (abbreviated as THz). In many-body systems, several of the relevant ...

(THz) * Electron paramagnetic/spin resonance (EPR, ESR) * Small-angle neutron scattering (SANS) * Rutherford backscattering spectrometry (RBS)

Macroscopic testing

A huge range of techniques are used to characterize various macroscopic properties of materials, including: *

Mechanical testing Mechanical testing covers a wide range of tests, which can be divided broadly into two types: # those that aim to determine a material's mechanical properties, independent of geometry. # those that determine the response of a structure to a given ...

, including tensile, compressive, torsional, creep, fatigue, toughness and hardness testing *

Differential thermal analysis Differential thermal analysis (DTA) is a thermoanalytic technique that is similar to differential scanning calorimetry. In DTA, the material under study and an inert reference are made to undergo identical thermal cycles, (i.e., same cooling or ...

(DTA) * Dielectric thermal analysis (DEA, DETA) * Thermogravimetric analysis (TGA) *

Differential scanning calorimetry Differential scanning calorimetry (DSC) is a thermoanalytical technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature. Both the sample and ref ...

(DSC) *

Impulse excitation technique The impulse excitation technique (IET) is a non-destructive material characterization technique to determine the elastic properties and internal friction of a material of interest. It measures the resonant frequencies in order to calculate the Youn ...

(IET) *

Ultrasound Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...

techniques, including

resonant ultrasound spectroscopy Resonant ultrasound spectroscopy (RUS) is a laboratory technique used in geology and material science to measure fundamental material properties involving elasticity. This technique relies on the fact that solid objects have natural frequencies at ...

and time domain

ultrasonic testing Ultrasonic testing (UT) is a family of non-destructive testing techniques based on the propagation of ultrasonic waves in the object or material tested. In most common UT applications, very short ultrasonic pulse-waves with center frequencies ...

methodsR. Truell, C. Elbaum and C.B. Chick., Ultrasonic methods in solid state physics New York, Academic Press Inc., 1969.

References

{{DEFAULTSORT:Characterization (Materials Science) Materials science