{"title":"通过冲击波工程剪裁哌啶-4-羧酸盐酸盐晶体的NLO特性:实验验证和DFT见解","authors":"S. Lakshmi , R.S. Priyadharshini , M. Saravanan","doi":"10.1016/j.mseb.2025.118756","DOIUrl":null,"url":null,"abstract":"<div><div>Single crystals of piperidine-4-carboxylic acid hydrochloride (4PCAHCl) were grown by <strong>slow evaporation</strong> and subjected to detailed characterization. The structural arrangement and unit cell parameters were determined using single-crystal X-ray diffraction (SXRD), while functional group identification was carried out via Fourier-transform infrared (FTIR) spectroscopy. Powder X-ray diffraction (PXRD) confirmed phase purity and crystallinity, and morphological insights were obtained using scanning electron microscopy (SEM). <strong>The influence of shock wave treatment at Mach 1.2 was specifically studied for its effect on the optical and nonlinear optical properties</strong>. UV–Vis–NIR spectroscopy of shock-treated crystals revealed enhanced transparency and a slightly reduced optical bandgap, consistent with improved π-electron delocalization and lattice reordering effects. Z-scan analysis showed an increased third-order nonlinear optical response, indicating improved nonlinear absorption and refraction. The laser damage threshold (LDT) was significantly elevated, reflecting enhanced optical endurance. Second harmonic generation (SHG) efficiency and phase-matching behaviour were also improved by shock exposure.</div><div>To support these findings, Density Functional Theory (DFT) calculations were performed, revealing a reduced HOMO–LUMO gap, increased dipole moment, and enhanced polarizability in the optimized structures. These theoretical insights corroborate the experimentally observed improvement in third-order susceptibility (χ<sup>(3)</sup>), and attribute the enhancement to shock-induced rehybridization, extended π-conjugation, and increased charge transfer between –NH<sup>+</sup> and –COOH groups.</div><div>These combined experimental and computational findings demonstrate that while the basic structural and chemical characteristics remain intact, shock wave treatment significantly enhances the optical and NLO performance of 4PCAHCl crystals, making them strong candidates for advanced photonic applications.</div></div>","PeriodicalId":18233,"journal":{"name":"Materials Science and Engineering: B","volume":"323 ","pages":"Article 118756"},"PeriodicalIF":4.6000,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Tailoring NLO properties of piperidine-4-carboxylic acid hydrochloride crystals via shockwave engineering: experimental validation and DFT insights\",\"authors\":\"S. Lakshmi , R.S. Priyadharshini , M. Saravanan\",\"doi\":\"10.1016/j.mseb.2025.118756\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Single crystals of piperidine-4-carboxylic acid hydrochloride (4PCAHCl) were grown by <strong>slow evaporation</strong> and subjected to detailed characterization. The structural arrangement and unit cell parameters were determined using single-crystal X-ray diffraction (SXRD), while functional group identification was carried out via Fourier-transform infrared (FTIR) spectroscopy. Powder X-ray diffraction (PXRD) confirmed phase purity and crystallinity, and morphological insights were obtained using scanning electron microscopy (SEM). <strong>The influence of shock wave treatment at Mach 1.2 was specifically studied for its effect on the optical and nonlinear optical properties</strong>. UV–Vis–NIR spectroscopy of shock-treated crystals revealed enhanced transparency and a slightly reduced optical bandgap, consistent with improved π-electron delocalization and lattice reordering effects. Z-scan analysis showed an increased third-order nonlinear optical response, indicating improved nonlinear absorption and refraction. The laser damage threshold (LDT) was significantly elevated, reflecting enhanced optical endurance. Second harmonic generation (SHG) efficiency and phase-matching behaviour were also improved by shock exposure.</div><div>To support these findings, Density Functional Theory (DFT) calculations were performed, revealing a reduced HOMO–LUMO gap, increased dipole moment, and enhanced polarizability in the optimized structures. These theoretical insights corroborate the experimentally observed improvement in third-order susceptibility (χ<sup>(3)</sup>), and attribute the enhancement to shock-induced rehybridization, extended π-conjugation, and increased charge transfer between –NH<sup>+</sup> and –COOH groups.</div><div>These combined experimental and computational findings demonstrate that while the basic structural and chemical characteristics remain intact, shock wave treatment significantly enhances the optical and NLO performance of 4PCAHCl crystals, making them strong candidates for advanced photonic applications.</div></div>\",\"PeriodicalId\":18233,\"journal\":{\"name\":\"Materials Science and Engineering: B\",\"volume\":\"323 \",\"pages\":\"Article 118756\"},\"PeriodicalIF\":4.6000,\"publicationDate\":\"2025-09-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Materials Science and Engineering: B\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0921510725007809\",\"RegionNum\":3,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Science and Engineering: B","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0921510725007809","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Tailoring NLO properties of piperidine-4-carboxylic acid hydrochloride crystals via shockwave engineering: experimental validation and DFT insights
Single crystals of piperidine-4-carboxylic acid hydrochloride (4PCAHCl) were grown by slow evaporation and subjected to detailed characterization. The structural arrangement and unit cell parameters were determined using single-crystal X-ray diffraction (SXRD), while functional group identification was carried out via Fourier-transform infrared (FTIR) spectroscopy. Powder X-ray diffraction (PXRD) confirmed phase purity and crystallinity, and morphological insights were obtained using scanning electron microscopy (SEM). The influence of shock wave treatment at Mach 1.2 was specifically studied for its effect on the optical and nonlinear optical properties. UV–Vis–NIR spectroscopy of shock-treated crystals revealed enhanced transparency and a slightly reduced optical bandgap, consistent with improved π-electron delocalization and lattice reordering effects. Z-scan analysis showed an increased third-order nonlinear optical response, indicating improved nonlinear absorption and refraction. The laser damage threshold (LDT) was significantly elevated, reflecting enhanced optical endurance. Second harmonic generation (SHG) efficiency and phase-matching behaviour were also improved by shock exposure.
To support these findings, Density Functional Theory (DFT) calculations were performed, revealing a reduced HOMO–LUMO gap, increased dipole moment, and enhanced polarizability in the optimized structures. These theoretical insights corroborate the experimentally observed improvement in third-order susceptibility (χ(3)), and attribute the enhancement to shock-induced rehybridization, extended π-conjugation, and increased charge transfer between –NH+ and –COOH groups.
These combined experimental and computational findings demonstrate that while the basic structural and chemical characteristics remain intact, shock wave treatment significantly enhances the optical and NLO performance of 4PCAHCl crystals, making them strong candidates for advanced photonic applications.
期刊介绍:
The journal provides an international medium for the publication of theoretical and experimental studies and reviews related to the electronic, electrochemical, ionic, magnetic, optical, and biosensing properties of solid state materials in bulk, thin film and particulate forms. Papers dealing with synthesis, processing, characterization, structure, physical properties and computational aspects of nano-crystalline, crystalline, amorphous and glassy forms of ceramics, semiconductors, layered insertion compounds, low-dimensional compounds and systems, fast-ion conductors, polymers and dielectrics are viewed as suitable for publication. Articles focused on nano-structured aspects of these advanced solid-state materials will also be considered suitable.