2000/10/21 by B. Groh, S. Dietrich · 1 citation
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Characterization and Applications of Magnetic Nanoparticles #Chemistry #Condensed matter physics #Crystal (programming language) #Crystal structure #Crystallography #Dielectric #Dipole #Ewald summation #Ferroelectricity #Ground state #Liquid crystal #Material Dynamics and Properties #Materials science #Molecular dynamics #Orthorhombic crystal system #Phase (matter) #Phase diagram #Physics #Quantum mechanics #Tetragonal crystal system #Thermodynamics #Vibration Control and Rheological Fluids #cond-mat.soft
paper · pdf · doi:10.1103/physreve.63.021203
submitted to Phys. Rev. E
arxiv created 2000/10/21 · openalex publication_date 2001/01/23 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 approximately 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.