• Neelam Rani
• Karan singh gill
• Atul Jain
• Sonia Devi

Characterization plays a pivotal role in understanding the structural, optical, mechanical, electrical, and nonlinear optical properties of crystalline materials. In recent years, single and polycrystalline materials have attracted significant attention due to their potential applications in optoelectronics, photonics, and nonlinear optical (NLO) devices. A comprehensive analysis of these materials requires the use of multiple complementary characterization techniques, each based on distinct physical and chemical principles.This review paper will give a brief introduction about various characterization techniques with fundamental physics/chemistry behind them. Various characterization techniques used in the present study are: (i) Powder X-ray diffractometer is used to find the structure of the grown crystals. (ii) High Resolution X-ray diffractometer is used to evaluate the crystalline perfection of the grown crystal. (iii) Spectroscopic methods (FTIR, NMR, PL, and UV-Vis-NIR) are used for qualitative and quantitative analyses of chemical compounds. (iv)The Impedance analyzer is used to measure the dielectric constant, dielectric energy loss of the grown crystals. (v) Vickers hardness tester equipped with a diamond square indenter is used to measure mechanical properties of the grown crystals. (vi) The Kurtz and Perry powder technique has been used to assess the relative second harmonic generation efficiency. (vii) Z-scan technique is used to determine the third harmonic of the grown crystals. (viii) Etching studies were done to reveal the dislocations in the grown crystal. (ix) Ion implantation was done to modify the physical property of the grown crystal and (x) Thermal studies were done to know the change in properties of the crystal with temperature. These techniques have been described in detail in the following section.

Etching ,Ion Implantation, Micro hardness, High resolution

"A REVIEW ON CHARACTERISATION TECHNIQUES ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.13, Issue 3, page no.a456-a471, March-2026, Available :http://www.jetir.org/papers/JETIR2603061.pdf

"A REVIEW ON CHARACTERISATION TECHNIQUES ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.13, Issue 3, page no. ppa456-a471, March-2026, Available at : http://www.jetir.org/papers/JETIR2603061.pdf