P. Girija,
- Research Scholar, Apex Professional University, Arunachal Pradesh., Arunachal Pradesh, India
Abstract
Nonlinear optical (NLO) materials exhibiting second harmonic generation have attracted considerable attention over the past few decades because of their technological significance in areas such as optical communication, signal processing, and instrumentation. Urea, being an important NLO material, presents challenges in crystal growth and handling due to its highly hygroscopic nature. Various derivatives of urea have been investigated for NLO applications, and some have shown promising potential in this field. Urea crystals have drawn interest from both theoretical and experimental researchers because of their nonlinear optical and piezoelectric properties [3–5]. Urea also finds application in photonics and has served as a reference material in the Diffusive Mixing of Organic Solution (DMOS) experiment conducted by NASA under microgravity conditions [6]. In addition, urea and its derivatives, such as Transparent single crystals of lead acetate-doped urea, an organic nonlinear optical (NLO) material, were successfully grown using the slow evaporation solution growth technique at room temperature. Triply distilled water was employed as the solvent to ensure high purity and controlled crystal formation. The incorporation of lead acetate as a dopant significantly influenced the growth behavior and physicochemical properties of the resulting crystals. The grown crystals exhibited good transparency, indicating their potential suitability for optical and photonic applications. A detailed investigation was conducted to assess the structural characteristics of the doped crystals.. Singlecrystal X-ray diffraction analysis confirmed the crystalline nature and revealed that the lead acetatedoped urea crystal belongs to the tetragonal crystal system. The lattice parameters were determined as a = 7.500 Å, b = 7.500 Å, and c = 7.549 Å, with a unit cell volume of 867 ų. The interaxial angles were found to be α = β = γ = 90°, consistent with the tetragonal symmetry. Comparison with pure urea crystals showed slight variations in the lattice parameters, suggesting successful incorporation of lead acetate impurities into the crystal lattice. Detailed refinement and data collection studies further supported the structural modification induced by the dopant. The presence of lead acetate is believed to alter intermolecular interactions within the crystal, resulting in subtle changes in the unit cell dimensions and overall crystal structure. These structural modifications may contribute to enhanced optical and nonlinear optical properties. The observed results demonstrate that lead acetate doping is an effective approach for tailoring the characteristics of urea crystals, making them promising candidates for applications in frequency conversion, optical modulation, and other advanced photonic devices. and N,N-dimethyl urea, have been explored as dopants in KDP crystals. Several studies have
Keywords: Transparent crystal, single crystal XRD, tetragonal, Urea, crystal structure
[This article belongs to International Journal of Crystalline Materials ]
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International Journal of Crystalline Materials
| Volume | 03 | |
| Issue | 02 | |
| Received | 17/06/2026 | |
| Accepted | 30/06/2026 | |
| Published | 10/07/2026 | |
| Publication Time | 23 Days |