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arXiv cond-mat/0010331cond-mat.soft
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晶体结构与偶极流体的冻结

Crystal structures and freezing of dipolar fluids

B. Groh, S. Dietrich

摘要:

我们研究了在T=0时具有嵌入点偶极子的球形粒子的经典系统的晶体结构。铁电基态能量的计算使用推广的埃瓦尔德求和技术。由于与非极性情况相比对称性降低,晶体从来不是严格的立方体。对于Stockmayer(即,Lennard-Jones加偶极)相互作用在增加偶极矩时发现了三个相:六方、体心正交和体心四方。一个更丰富的相图出现的偶极软球与一个纯粹的排斥逆幂律势$\sim r^{-n}$。在指数$n=12$附近发生定性不同的相位序列之间的交叉。结果适用于电流变液和磁流变液。除了精确的基态分析,我们研究了冻结的Stockmayer流体的密度泛函理论。

英文摘要:

We investigate the crystal structure of classical systems of spherical particles with an embedded point dipole at T=0. The ferroelectric ground state energy is calculated using generalizations of the Ewald summation technique. Due to the reduced symmetry compared to the nonpolar case the crystals are never strictly cubic. For the Stockmayer (i.e., Lennard-Jones plus dipolar) interaction three phases are found upon increasing the dipole moment: hexagonal, body-centered orthorhombic, and body-centered tetragonal. An even richer phase diagram arises for dipolar soft spheres with a purely repulsive inverse power law potential $\sim r^{-n}$. A crossover between qualitatively different sequences of phases occurs near the exponent $n=12$. The results are applicable to electro- and magnetorheological fluids. In addition to the exact ground state analysis we study freezing of the Stockmayer fluid by density-functional theory.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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