{"title":"On the nitrogen concentration and crystal size dependence of lattice thermal conductivity in diamond thin and nanofilms","authors":"N.K. Ali , M.S. Omar , S.O. Yousf","doi":"10.1016/j.diamond.2025.112340","DOIUrl":null,"url":null,"abstract":"<div><div>This work comprehensively analyses lattice thermal conductivity (LTC) in diamond materials, focusing on the dual influence of nitrogen impurities and crystal size. Using a modified Debye-Callaway model, theoretical calculations are performed for two groups of diamond specimens. The first group comprises single-crystal diamonds with varying nitrogen concentrations, ranging from nearly pure to highly doped specimens. The second group comprises single crystals, microfilms, and nanofilms of varying sizes, allowing for an investigation of size-dependent effects. The study systematically examines the contributions of various phonon-scattering mechanisms, including phonon-phonon interactions (Normal and Umklapp processes), point defects, isotopes, boundary scattering, dislocations, phonon-electron interactions, and phonon resonance scattering for both longitudinal and transverse phonon modes. Notably, phonon resonance scattering plays a significant role in LTC reduction at low temperatures, where phonons interact with localized defect-induced vibrational modes. Nitrogen impurities act as strong scattering centers, significantly disrupting the lattice structure and reducing LTC. The degree of reduction correlates with nitrogen concentration, defect density, and platelet configurations. Crystal size is another critical factor, as smaller samples exhibit enhanced boundary scattering, resulting in a pronounced decline in LTC, particularly at nanoscale dimensions. The work further identifies systematic relationships between LTC, nitrogen concentration, and crystal size, providing key mathematical models to predict thermal transport behaviour. These findings offer valuable insights into tailoring diamond materials for advanced applications in thermal management, high-power electronics, and energy systems, where precise control of thermal properties is essential.</div></div>","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"155 ","pages":"Article 112340"},"PeriodicalIF":4.3000,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Diamond and Related Materials","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0925963525003978","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, COATINGS & FILMS","Score":null,"Total":0}
引用次数: 0
Abstract
This work comprehensively analyses lattice thermal conductivity (LTC) in diamond materials, focusing on the dual influence of nitrogen impurities and crystal size. Using a modified Debye-Callaway model, theoretical calculations are performed for two groups of diamond specimens. The first group comprises single-crystal diamonds with varying nitrogen concentrations, ranging from nearly pure to highly doped specimens. The second group comprises single crystals, microfilms, and nanofilms of varying sizes, allowing for an investigation of size-dependent effects. The study systematically examines the contributions of various phonon-scattering mechanisms, including phonon-phonon interactions (Normal and Umklapp processes), point defects, isotopes, boundary scattering, dislocations, phonon-electron interactions, and phonon resonance scattering for both longitudinal and transverse phonon modes. Notably, phonon resonance scattering plays a significant role in LTC reduction at low temperatures, where phonons interact with localized defect-induced vibrational modes. Nitrogen impurities act as strong scattering centers, significantly disrupting the lattice structure and reducing LTC. The degree of reduction correlates with nitrogen concentration, defect density, and platelet configurations. Crystal size is another critical factor, as smaller samples exhibit enhanced boundary scattering, resulting in a pronounced decline in LTC, particularly at nanoscale dimensions. The work further identifies systematic relationships between LTC, nitrogen concentration, and crystal size, providing key mathematical models to predict thermal transport behaviour. These findings offer valuable insights into tailoring diamond materials for advanced applications in thermal management, high-power electronics, and energy systems, where precise control of thermal properties is essential.
期刊介绍:
DRM is a leading international journal that publishes new fundamental and applied research on all forms of diamond, the integration of diamond with other advanced materials and development of technologies exploiting diamond. The synthesis, characterization and processing of single crystal diamond, polycrystalline films, nanodiamond powders and heterostructures with other advanced materials are encouraged topics for technical and review articles. In addition to diamond, the journal publishes manuscripts on the synthesis, characterization and application of other related materials including diamond-like carbons, carbon nanotubes, graphene, and boron and carbon nitrides. Articles are sought on the chemical functionalization of diamond and related materials as well as their use in electrochemistry, energy storage and conversion, chemical and biological sensing, imaging, thermal management, photonic and quantum applications, electron emission and electronic devices.
The International Conference on Diamond and Carbon Materials has evolved into the largest and most well attended forum in the field of diamond, providing a forum to showcase the latest results in the science and technology of diamond and other carbon materials such as carbon nanotubes, graphene, and diamond-like carbon. Run annually in association with Diamond and Related Materials the conference provides junior and established researchers the opportunity to exchange the latest results ranging from fundamental physical and chemical concepts to applied research focusing on the next generation carbon-based devices.