The process starts with the generation and acceleration of electrons. Usually, a filament of tungsten or lanthanum hexaboride emits electrons by thermionic emission. These electrons are accelerated by an anode to high energies, typically in the range of 1-30 keV, to form a focused electron beam. This high-energy beam is crucial for subsequent interactions with the sample.

The resulting electron beam is then carefully focused by a set of electromagnetic lenses. These lenses act similarly to optical microscope lenses and control the direction of the electron beam to modify its size and shape. This focusing is required for achieving high resolution, enabling the acquisition of a detailed picture of the sample's surface.

The focused electron beam scans across the surface of the sample in a raster pattern, similar to the way in which a television screen scans. Scanning is achieved by the deflection of the electron beam from electromagnetic coils. Because of this very accurate scanning, it is possible to collect the signal at defined points on the sample surface, and a high-resolution 2D image can be generated.

Signals such as secondary electrons produced during the interaction between the high-energy electron beam and the specimen are low-energy electrons ejected from the atoms in the surface of the specimen; these are the SEs that carry the important topographic information. Other examples are the backscattered electrons, BSE, which are high-energy electrons that are scattered backward from the atoms in the specimen. They give compositional information since the intensity depends on the atomic number of the elements involved. Further, characteristic X-rays are produced by the ionization of atoms in the sample by incident electrons, enabling the analysis of elements.

Special detectors then collect these emitted signals carefully: SE, BSE, and X-rays. A 2D image is then developed on the computer screen based on the intensity of the detected signal at each point in the area scanned. The different detectors may visualize different features of the sample, such as topography, composition, or crystal structure, enabling a full understanding of the characteristics of the sample.

• Surface roughness: The size and distribution of surface irregularities.

• Morphological features: Such as cracks, voids, and inclusions that may have formed during processing or due to external stresses.

• Fracture patterns: For example, ductile or brittle fracture surfaces, which may appear as a smooth, shiny surface or rough, jagged patterns depending on the material's properties.

An example of the SEM imaging for surface morphology analysis is ilmenute surface analysis. In surface morphology analysis of ilmenite, SEM images reveal cracks in the sample, which are crucial for understanding the mechanical behavior of ilmenite. Many of the surface furrows that indicate operations or environmental influences on the mineral represent mechanical degradation or weathering. In addition, the characteristics of ilmenite particles and their potential uses are clarified by examining the particle shape through SEM and considering its mineralogical properties. 

A) Specimen preparation
First, an appropriate sample is selected to investigate such characteristics as cracks, shape of particles and furrows. The sample is then attached to the stub by using the conductive carbon double sided tape to provide the conduction path through the pads on the SEM stubs. In the case of ilmenite, no preparation is necessary, but for other non-conductive materials, gold or platinum coatings may be necessary to eliminate charging effects. After that, the sample is dried and washed to eliminate moisture that may interfere with image formation. Last but not the least, depending on the nature and type of the sample the sample may be broken or reduced mechanically by fracturing, trimming or cutting to allow direct interaction of the electron beam with the surface features of interest.

B) Imaging process in SEM

i) Secondary Electron Imaging (SEI):
SEI measures secondary electrons produced from the surface of ilmenite. It is widely applied in the analysis of topographical relief, roughness and other surface irregularities such as cracks for which SEI assists in determination of the depth and orientation of cracks on the surface. For particle shape and morphology, gives geometrical description of the ilmenite particles.

ii) Backscattered Electron Imaging (BSEI):
BSEI collects electrons which are back scattered because of their interaction with the sample. It offers information about compositional contrast where materials with high atomic number such as titanium and iron in ilmenite will be bright while those with low atomic number will be dark. After that, morphology and roughness, BSEI images are especially helpful in studying the roughness and variations in the chemical composition that may be unnoticed in SEI.