Anisotropic magnetic field-temperature phase diagrams in CeCoSi

Hidaka, Hiroyuki*; Yanagiya, Shun*; Onodera, Shintaro*; Yanagisawa, Tatsuya*; Amitsuka, Hiroshi*; Tanida, Hiroshi*; Ishitobi, Takayuki

We investigated the magnetic-field direction anisotropy of the unknown ordered phase in the tetragonal compound CeCoSi through bulk physical property measurements. The anisotropy in the field direction, previously identified in X-ray diffraction experiments, where a field-induced phase appears along [100] but not along [110], was confirmed in the bulk properties. Combining these experimental results with Landau theory, we infer that the field-induced phase in the [100] direction emerges under an infinitesimally small magnetic field.