Study of the ferromagnetic quantum phase transition in Ce_3−xMg_xCo₉

Abstract

The Ce3−xMgxCo9 system evolves from a Pauli paramagnetic ground state for x = 0 to a ferromagnetic ground state for x ≈ 0.80 in single phase, polycrystalline samples [Phys. Rev. Applied 9, 024023 (2018)]. In order to better understand this behavior, single crystalline samples of Ce3−xMgxCo9 for x = 0.01, 0.16, 0.24, 0.35, 0.43 and 0.50 were grown using the flux growth technique, and electrical transport and magnetic properties were studied. The T C -x phase diagram we infer shows that the system has a quantum phase transition near x = 0.35, transforming to a ferromagnetic ground state.

Impact of GO on Non-stoichiometric Mg0.85 K0.3Fe2O4 Ferrite Nanoparticles

“…The distribution of Mg 0.85 K 0.3 Fe 2 O 4 nanoparticles on the GO surface decreases the spin disorder. Consequently, the domains become well-oriented [40] and the ferromagnetic region becomes wider compared to the paramagnetic one.…”

Robust antiferromagnetism in Y$_2$Co$_3$

“…As Figure 1 suggests, compounds with 60 or more atomic percent of Cobalt are much more often ferromagnetic than antiferromagnetic. While Nature delights in exceptions to such simple classifications, such as the surprisingly paramagnetic CeCo 3 [36][37][38], one would naively expect antiferromagnetic behavior in this stoichiometry regime to be the province of electronegative anions such as Oxygen, Sulfur or the Fluorine group. Yttrium, by contrast, is known substantially for its mineral occurrence with the "rare earth" family, and similar chemical properties, despite its lack of f electrons.…”