[5] At temperatures above 50 K its properties are typical of a Kondo metal, with metallic electrical conductivity characterized by strong electron scattering, whereas at low temperatures, it behaves as a non-magnetic insulator with a narrow band gap of about 4–14 meV.

[6] The cooling-induced metal-insulator transition in SmB6 is accompanied by a sharp increase in thermal conductivity, peaking at about 15 K. The reason for this increase is that electrons do not contribute to thermal conductivity at low temperatures, which is instead dominated by phonons.

[7] By the twenty first century condensed matter physicists grew more interested in SmB6 with claims that it may be a topological insulator.

[11] The increasing electrical resistance with a reduction in temperature indicates that the material behaves as an insulator; however, recent measurements reveal a Fermi surface (an abstract boundary of electrons in momentum space) characteristic of a good metal, indicating a more exotic dual metal-insulating ground state.

[12][15][13] While it has been argued that quantum oscillations on samples grown from aluminium flux[16] may arise from aluminum inclusions,[17] such an explanation is excluded for samples grown by the image furnace method[12][14] rather than by the flux growth method.