Tricritical wings in UGe2: A microscopic interpretation

• Published in: Journal of magnetism and magnetic materials 2016-02, Vol.400, p.27-30
• Main Authors: Abram, Marcin, Wysokiński, Marcin M., Spałek, Józef
• Format: Article
• Language: English
• Subjects: 71.10.-w; 71.27.+a; 75.30.kz; Critical points; Ferromagnetism; Heavy fermions; UGe2
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2015.07.017

In the present work we analyze the second order transition line that connects the tricritical point and the quantum critical ending point on the temperature–magnetic-field plane in UGe2. For the microscopic modeling we employ the Anderson lattice model recently shown to provide a fairly complete description of the full magnetic phase diagram of UGe2 including all the criticalities. The shape of the so-called tricritical wings, i.e. surfaces of the first-order transitions, previously reported by us to quantitatively agree with the experimental data, is investigated here with respect to the change of the total filling and the Landé factor for f electrons which can differ from the free electron value. The analysis of the total filling dependence demonstrates sensitivity of our prediction when the respective positions of the critical ending point at the metamagnetic transition and tricritical point are mismatched as compared to the experiment. •We model microscopically the tricritical wings boundaries in UGe2.•Agreement with the experiment is investigated with respect to the total filling.•Model is studied with respect to the different value of g-factor for f-electrons.