Пожалуйста, используйте этот идентификатор, чтобы цитировать или ссылаться на этот ресурс:
http://elar.urfu.ru/handle/10995/26830
Название: | Thermodynamics of ferrofluids in applied magnetic fields |
Авторы: | Elfimova, E. A. Ivanov, A. O. Camp, P. J. |
Дата публикации: | 2013 |
Библиографическое описание: | Elfimova E. A. Thermodynamics of ferrofluids in applied magnetic fields / E. A. Elfimova, A. O. Ivanov, P. J. Camp // Physical Review E - Statistical, Nonlinear, and Soft Matter Physics. — 2013. — Vol. 88. — № 4. |
Аннотация: | The thermodynamic properties of ferrofluids in applied magnetic fields are examined using theory and computer simulation. The dipolar hard sphere model is used. The second and third virial coefficients (B2 and B3) are evaluated as functions of the dipolar coupling constant λ, and the Langevin parameter α. The formula for B3 for a system in an applied field is different from that in the zero-field case, and a derivation is presented. The formulas are compared to results from Mayer-sampling calculations, and the trends with increasing λ and α are examined. Very good agreement between theory and computation is demonstrated for the realistic values λ≤2. The analytical formulas for the virial coefficients are incorporated in to various forms of virial expansion, designed to minimize the effects of truncation. The theoretical results for the equation of state are compared against results from Monte Carlo simulations. In all cases, the so-called logarithmic free energy theory is seen to be superior. In this theory, the virial expansion of the Helmholtz free energy is re-summed in to a logarithmic function. Its success is due to the approximate representation of high-order terms in the virial expansion, while retaining the exact low-concentration behavior. The theory also yields the magnetization, and a comparison with simulation results and a competing modified mean-field theory shows excellent agreement. Finally, the putative field-dependent critical parameters for the condensation transition are obtained and compared against existing simulation results for the Stockmayer fluid. Dipolar hard spheres do not undergo the transition, but the presence of isotropic attractions, as in the Stockmayer fluid, gives rise to condensation even in zero field. A comparison of the relative changes in critical parameters with increasing field strength shows excellent agreement between theory and simulation, showing that the theoretical treatment of the dipolar interactions is robust. © 2013 American Physical Society. |
Ключевые слова: | APPLIED MAGNETIC FIELDS CONDENSATION TRANSITION DIPOLAR HARD SPHERES DIPOLAR INTERACTION LOGARITHMIC FUNCTIONS MODIFIED MEAN FIELDS THEORETICAL TREATMENTS THIRD VIRIAL COEFFICIENTS COMPUTER SIMULATION CONDENSATION EQUATIONS OF STATE EXPANSION FREE ENERGY MAGNETIC FIELDS MAGNETIC FLUIDS MEAN FIELD THEORY MONTE CARLO METHODS THERMODYNAMICS COMPUTATION THEORY |
URI: | http://elar.urfu.ru/handle/10995/26830 |
Идентификатор SCOPUS: | 84886647760 |
Идентификатор WOS: | 000326118200005 |
Идентификатор PURE: | 856532 |
ISSN: | 1539-3755 |
DOI: | 10.1103/PhysRevE.88.042310 |
Располагается в коллекциях: | Научные публикации, проиндексированные в SCOPUS и WoS CC |
Файлы этого ресурса:
Файл | Описание | Размер | Формат | |
---|---|---|---|---|
scopus-2013-0063.pdf | 530,41 kB | Adobe PDF | Просмотреть/Открыть |
Все ресурсы в архиве электронных ресурсов защищены авторским правом, все права сохранены.