Magnetic Field and Dilution Effects on the Phase Diagrams of Simple Statistical Models for Nematic Biaxial Systems

Autor(es)

Rodrigues, Daniel D. ^[1] ; Vieira, Andre P. ^[1] ; Salinas, Silvio R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Fis, Rua Matao 1371, BR-05508090 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CRYSTALS; v. 10, n. 8 AUG 2020.
• Citações Web of Science: 0

Resumo

We use a simple statistical model to investigate the effects of an applied magnetic field and of the dilution of site elements on the phase diagrams of biaxial nematic systems, with an emphasis on the stability of the Landau multicritical point. The statistical lattice model consists of intrinsically biaxial nematogenic units, which interact via a Maier-Saupe potential, and which are characterized by a discrete choice of orientations of the microscopic nematic directors. According to previous calculations at zero field and in the absence of dilution, we regain the well-known sequence of biaxial, uniaxial, and disordered structures as the temperature is increased, and locate the Landau point. We then focus on the topological changes induced in the phase diagram by the application of an external magnetic field, and show that the Landau point is destabilized by the presence of an applied field. On the other hand, in the absence of a field, we show that only a quite strong dilution of nematic sites is capable of destabilizing the Landau point. (AU)

• Processo FAPESP: 17/09566-8 - Modelos microscópicos para cristais líquidos nemáticos diluídos
• Beneficiário: Daniel Dias Rodrigues
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica