Magnetic Order in Organic Dirac Electron System α-(BETS)2I3

Magnetic torque measurements were conducted to investigate the magnetic properties of organic conductor alpha-(BETS)(2)I-3, a candidate material that forms Dirac electron states under ambient pressure, and alpha-(BEDT-TTF)(2)I-3, where Dirac fermions are realized under high pressure. In alpha-(BEDT-TTF)(2)I-3, magnetic torque reflecting the anisotropic diamagnetism is observed in the nonmagnetic charge-ordered state. The complex torque curves of alpha-(BETS)(2)I-3, observed only at low temperatures and low magnetic fields, provide the first evidence for the existence of magnetic order. The clear change in the torque amplitude observed at the metal-insulator crossover temperature suggests that this crossover is related to the magnetic nature of alpha-(BETS)(2)I-3.

Automated summary

In this study, magnetic torque measurements were used to investigate the magnetic properties of the organic conductors alpha-(BETS)(2)I-3 and alpha-(BEDT-TTF)(2)I-3. The magnetic torque reflecting anisotropic diamagnetism was observed in alpha-(BEDT-TTF)(2)I-3, while complex torque curves in alpha-(BETS)(2)I-3 provided the first evidence for the existence of magnetic order. The observed change in torque amplitude at the metal-insulator crossover temperature suggests a relationship between this crossover and the magnetic nature of alpha-(BETS)(2)I-3.