Tailoring NLO properties of piperidine-4-carboxylic acid hydrochloride crystals via shockwave engineering: experimental validation and DFT insights

IF 4.6 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: B Pub Date : 2025-09-15 DOI:10.1016/j.mseb.2025.118756

S. Lakshmi , R.S. Priyadharshini , M. Saravanan

{"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}

引用次数: 0

Abstract

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.

查看原文本刊更多论文

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

采用慢蒸发法制备了盐酸哌啶-4-羧酸（4PCAHCl）单晶，并对其进行了详细的表征。利用单晶x射线衍射（SXRD）确定了结构排列和单体参数，利用傅里叶变换红外光谱（FTIR）鉴定了官能团。粉末的x射线衍射（PXRD）证实了相纯度和结晶度，并通过扫描电镜（SEM）获得了形貌信息。具体研究了1.2马赫下冲击波处理对光学和非线性光学特性的影响。紫外-可见-近红外光谱显示，经过冲击处理的晶体透明度增强，光学带隙略有减小，这与π电子离域和晶格重排序效应的改善相一致。z -扫描分析显示三阶非线性光学响应增加，表明非线性吸收和折射改善。激光损伤阈值（LDT）显著提高，反映出增强的光耐力。冲击暴露也改善了二次谐波产生（SHG）效率和相位匹配行为。为了支持这些发现，进行了密度泛函理论（DFT）计算，揭示了优化结构中减小的HOMO-LUMO间隙，增加的偶极矩和增强的极化率。这些理论见解证实了实验观察到的三阶磁化率的改善（χ(3)），并将这种增强归因于激波诱导的再杂化、π共轭扩展以及-NH +和-COOH基团之间电荷转移的增加。这些实验和计算结果表明，在基本结构和化学特性保持不变的情况下，冲击波处理显著提高了4PCAHCl晶体的光学和NLO性能，使其成为先进光子应用的有力候选者。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Materials Science and Engineering: B 工程技术-材料科学：综合

CiteScore

5.60

自引率

2.80%

发文量

481

审稿时长

3.5 months

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.