GB/T 22461.1-2023 Surface chemical analysis - Vocabulary - Part 1: General terms and terms used in spectroscopy
1 Scope
This document defines terms for scanning probe microscopy in the field of surface chemical analysis and gives A list of relevant abbreviations (see Annex A).
This document is applicable to the teaching, scientific research, design, manufacture, preparation of relevant technical documents and books and technical exchanges related to scanning probe microscopy in surface chemical analysis.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
3.1 Terms related to scanning probe microscopy methods
3.1
apertureless Raman microscopy
method of microscopy involving the acquisition of Raman spectroscopic data utilizing a near-field (5.88) optical source and based upon a metal tip (5.120) in close proximity to the sample surface illuminated with suitably polarized light
3.2
atomic-force microscopy; AFM
scanning force microscopy; SFM (decline)
method for imaging surfaces by mechanically scanning their surface contours, in which
the deflection of a sharp tip (5.120) sensing the surface forces, mounted on a compliant
cantilever (5.18), is monitored
Note 1: AFM can provide a quantitative height image (5.69) of both insulating and conducting surfaces.
Note 2: Some AFM instruments move the sample in the x‑, y‑ and z‑directions while keeping the tip position constant and others move the tip while keeping the sample position constant.
Note 3: AFM can be conducted in vacuum, a liquid, a controlled atmosphere, or air. Atomic resolution may be attainable with suitable samples, with sharp tips, and by using an appropriate imaging mode.
Note 4: Many types of force can be measured, such as the normal forces (5.91) or the lateral (5.77), friction (5.62), or shear force. When the latter is measured, the technique is referred to as lateral (3.1.13), frictional (3.1.11), or shear force microscopy (3.1.37). This generic term encompasses all of the types of force microscopy listed in Annex A.
Note 5: AFMs can be used to measure surface normal forces at individual points in the pixel array used for imaging.
Note 6: For typical AFM tips with radii < 100 nm, the normal force should be less than about 0.1 μN, depending on the sample material, or irreversible surface deformation and excessive tip wear occur.
3.3
chemical-force microscopy; CFM
LFM (3.1.13) or AFM (3.1.2) mode in which the deflection of a sharp probe tip (5.120),
functionalized to provide interaction forces with specific molecules, is monitored
Note : LFM is the most popularly used mode.
3.4
conductive-probe atomic-force microscopy; CPAFM
CAFM decline
C-AFM decline
AFM (3.1.2) mode in which a conductive probe (5.109) is used to measure both
topography and electric current between the tip (5.120) and the sample
Note: CPAFM is a secondary imaging mode derived from contact AFM that characterizes conductivity variations across medium to low conducting and semiconducting materials. Typically, a DC bias is applied to the tip, and the sample is held at ground potential. While the z feedback signal is used to generate a normal contact AFM topography image (5.69), the current passing between the tip and the sample is measured to generate the conductive AFM image.
3.5
current-imaging tunnelling spectroscopy; CITS
method in which the STM tip is held at a constant height above the surface, while the bias voltage, V, is scanned and the tunnelling current, I, is measured and mapped
Note 1: The constant height is usually maintained by gating the feedback loop so that it is only active for some proportion of the time; during the remaining time, the feedback loop is switched off and the applied tip bias is ramped and the current is measured.
Note 2y: See I-V spectroscopy (5.74).
3.6
dynamic-mode; AFM
dynamic-force microscopy; DFM
AFM (3.1.2) mode in which the relative positions of the probe tip (5.120) and sample vary in a sinusoidal manner at each point in the image (5.69)
Note 1: The sinusoidal oscillation is usually in the form of a vibration in the z‑direction and is often driven at a frequency close to, and sometimes equal to, the cantilever resonance frequency.
Note 2: The signal measured can be the amplitude, the phase shift, or the resonance frequency shift of the cantilever.
3.7
electrostatic-force microscopy
electric-force microscopy (decline)
AFM (3.1.2) mode in which a conductive probe (5.109) is used to map both topography and electrostatic force between the tip (5.120) and the sample surface
3.8
electrochemical atomic-force microscopy; EC-AFM
AFM (3.1.2) mode in which a conductive probe (5.109) is used in an electrolyte
solution to measure both topography and electrochemical current
3.9
electrochemical scanning tunnelling microscopy; EC-STM
STM (3.1.34) mode in which a coated tip (5.120) is used in an electrolyte solution
to measure both topography and electrochemical current
3.10
frequency modulation atomic-force microscopy; FM-AFM
dynamic-mode AFM (3.1.6) in which the shift in resonance frequency (5.134) of the probe
assembly (5.20) is monitored and is adjusted to a set point using a feedback circuit
3.11
frictional-force microscopy; FFM
SPM (3.1.30) mode in which the friction force (5.62) is monitored
Note: The friction force can be detected in a static or frequency-modulated mode. Information on the tilt azimuthal variation of the frictional force needs the static mode.
3.12
Kelvin-probe force microscopy; KPFM
KFM (decline)
dynamic-mode AFM (3.1.6) using a conducting probe tip to measure spatial or temporal
changes in the relative electric potentials of the tip and the surface
Note: Changes in the relative potentials reflect changes in the surface work function.
3.13
lateral-force microscopy; LFM
SPM (3.1.30) mode in which surface contours are scanned with a probe assembly (5.20) while monitoring the lateral forces exerted on the probe tip (5.120) by observation of the torsion of the cantilever (5.18) arising as a result of those forces
Note: The lateral forces can be detected in a static or frequency-modulated mode. Information on the tilt azimuth of surface molecules needs the static mode.
3.14
magnetic dynamic-force microscopy; MDFM
magnetic AC mode (decline)
MAC mode (decline)
AFM (3.1.2) mode in which the probe (5.109) is oscillated by using a magnetic force (5.80)
3.15
magnetic-force microscopy; MFM
AFM (3.1.2) mode employing a probe assembly (5.20) that monitors both atomic forces and magnetic interactions between the probe tip (5.120) and a surface
3.16
magnetic-resonance force microscopy; MRFM
AFM (3.1.2) imaging mode in which magnetic signals are mechanically detected by using a cantilever (5.18) at resonance and the force arising from nuclear or electronic spin in the sample is sensitively measured
3.17
near-field scanning optical microscopy; NSOM
scanning near-field optical microscopy; SNOM
method of imaging surfaces optically in transmission or reflection by mechanically scanning an optically active probe (5.109) much smaller than the wavelength of light over
the surface while monitoring the transmitted or reflected light or an associated signal in the near-field (5.88) regime
Note 1: See scattering NSOM (3.1.36), scattering SNOM (3.1.36).
Note 2: Topography is important and the probe is scanned at constant height. Usually, the probe is oscillated in the shear mode to detect and set the height.
Note 3: Where the extent of the optical probe is defined by an aperture (5.5), the aperture size is typically in the range of 10 nm to 100 nm, and this largely defines the resolution. This form of instrument is often called an aperture NSOM or aperture SNOM to distinguish it from a scattering NSOM (3.1.36) or scattering SNOM (3.1.36) [previously called apertureless NSOM (3.1.36) or apertureless SNOM (3.1.36)], although, generally, the adjective “aperture” is omitted. In the apertureless form, the extent of the optically active probe is defined by an illuminated sharp metal or metal-coated tip (5.120) with a radius typically in the range of 10 nm to 100 nm, and this largely defines the resolution.
Note 4: In addition to the optical image (5.69), NSOM can provide a quantitative image of the surface contours similar to that available in AFM (3.1.2) and allied scanning probe techniques.
Note 5: This generic term encompasses all of the types of near-field microscopy listed in Clause 2.
3.18
non-contact atomic-force microscopy; NC-AFM
dynamic-mode AFM (3.1.6) in which the probe tip (5.120) is operated at such a distance from the surface that it samples the weak, attractive van der Waals or other forces
Note: Forces in this mode are very low and are best for studying soft materials or avoiding cross-contamination of the tip and the surface.
3.19
photothermal micro-spectroscopy; PTMS
SThM mode in which the probe (5.109) detects the photothermal response of a sample
exposed to infrared light to obtain an absorption spectrum
Note: The infrared light can be either from a tuneable monochromatic source or from a broadband source set up as part of a Fourier transform infrared spectrometer. In the latter case, the photothermal temperature fluctuations can be measured as a function of time to provide an interferogram which is Fourier transformed to give the spectrum of sub‑micron‑sized regions of the sample.
