کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8023107 | 1517422 | 2018 | 86 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Phonons and anomalous thermal expansion behaviour in crystalline solids
ترجمه فارسی عنوان
فونونها و رفتار گسترش انحصاری حرارتی در جامدات بلوری
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کلمات کلیدی
thermal expansion - انبساط حرارتیNegative thermal expansion - انبساط حرارتی منفیphonon density of states - تراکم فونون ایالاتLattice dynamics - دینامیک لبهPhonon dispersion relation - رابطه پراکندگی فونونSpecific heat - ظرفیت گرمایی یا ظرفیت حرارتیPhonon - فونونEquation of state - معادله حالت Inelastic neutron scattering - پراکندگی نوترون ناپایدار
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فناوری نانو (نانو تکنولوژی)
چکیده انگلیسی
Anomalous thermal expansion behaviour of several open frame-work compounds has been extensively investigated using the techniques of inelastic neutron scattering and lattice dynamics. These compounds involve increasing level of structural complexity and flexibility, which leads to increased values of thermal expansion coefficients approaching colossal values. In several compounds, neutron inelastic scattering experiments have produced quantitative estimates of the anharmonicity of phonons over a range of low energies, and thereby explained the observed thermal expansion quantitatively. The anharmonicity is found to be an order of magnitude larger than that in usual materials. Lattice dynamical calculations have correctly predicted the observed anharmonicity in the neutron experiments and revealed the overall nature of phonons involved. In compounds showing negative thermal expansion, the phonons responsible have rather low energies up to 10â¯meV. In most compounds, the anharmonic phonons span all over the Brillouin zone, while in some cases the specific phonons are limited to certain wave-vectors. The nature of specific phonons responsible for anomalous behavior is found to be different in all these compounds. These phonons generally involve transverse vibrations, librations and internal distortions of the polyhedral units. The paper reviews recent advances in the understanding of anomalous thermal expansion behaviour.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Progress in Materials Science - Volume 92, March 2018, Pages 360-445
Journal: Progress in Materials Science - Volume 92, March 2018, Pages 360-445
نویسندگان
R. Mittal, M.K. Gupta, S.L. Chaplot,