Étude de la phase isolant topologique chez le composé demi-Heusler GdBiPt
In this thesis will be discussed the study of a new way of characterizing state of matter called a topological insulator. We have mainly investigated whether the ternary compound GdBiPt, from the family of half-Heusler compounds, is an antiferromagnetic topological insulator. An analysis of the magnetic susceptibility and the specific heat of the material shows the presence of an antiferromagnetic transition at 8.85(3) K. A measurement of the anisotropy of the susceptibility shows that plan of spins are ordered according to the crystalline direction (1,1,1) and finally, measurements of electronic re- sistivity and Hall effect indicate that we have a semimetallic material when we are in the presence of antiferromagnetism. At the present, these experiments do not allow us to as- sociate this metallic state with the surface states associated with the topological insulator state of matter.
GdBiPt Topological insulator Half-Heusler antiferromagnetism