[19p-437-1~15] 9.5 New functional materials and new phenomena

△ [19p-437-4] Unconventional anisotropic magnetoresistance effect in antiferromagnet CaMn₂Bi₂ and influence of doping nonmagnetic elements

〇Takahiro Urata¹, Naoya Ishikawa¹, Takafumi Hatano¹, Kazumasa Iida¹, Tatsunori Okada², Hiroshi Ikuta¹ (1.Nagoya Univ., 2.IMR, Tohoku Univ.)

Keywords:Anisotropic magnetoresistance, Spin orbit coupling, Spin frustration

The interaction between local spins and conduction electrons is the basic ingredient of spintronics application. An intriguing question is how this interaction affects the transport properties in spin frustrated systems but little is known because most of such systems are insulating. CaMn₂Bi₂ is an antiferromagnetic semiconductor with a corrugated honeycomb structure. Owing to this structure, it is thought as a spin frustrated system and provides a novel playground to investigate interaction between frustrated spins and conduction electrons.
In this study we found a large anisotropic magnetoresistance effect in single crystalline CaMn₂Bi₂ at low temperature, which intriguingly depends nonmonotonically on the field strength. The origin of this magnetoresistance effect, and the effect of substituting a nonmagnetic element for Mn or Bi on magnetism and transport properties will be discussed in this presentation.