Intrinsic diamagnetism in the Weyl semimetal TaAs

• TaAs crystals exhibit intrinsic diamagnetism.
• A minimum in magnetization as a function of temperature is revealed.
• The intrinsic properties of the Weyl nodes are concealed in bulk TaAs.
• The samples are proposed to be as thin as possible to study the Weyl nodes.

We investigate the magnetic properties of TaAs, a prototype Weyl semimetal. TaAs crystals show diamagnetism with magnetic susceptibility of about −7×10−7 emu/(g Oe) at 5 K. A general feature is the appearance of a minimum at around 185 K in magnetization measurements as a function of temperature, which resembles that of graphite. No phase transition is observed in the temperature range between 5 K and 400 K.