Accurate determination of Curie temperature in helimagnet FeGe (Vol. 48, No. 4)

Cubic helimagnet FeGe, the prototype of skyrmion materials near room temperature, has emerged and may impact future information technology. The magnetic entropy change (MEC) of helimagnet FeGe and the close relationship between the MEC and critical exponents of a second-order phase transition were studied. A relatively small MEC under external high magnetic field indicates the coexistence and competition between exchange anisotropy and magneto-crystalline anisotropy, and a stable balance is formed in the precursor region when the applied magnetic field cannot completely transform FeGe into a single magnetic structure phase. Based on the obtained magnetic entropy change and critical exponents, an accurate Curie temperature of helimagnet FeGe under zero magnetic field is confirmed to be 279.1 K, lower than 282 K deduced directly from the derivative magnetic susceptibility and higher than 278.2 K previously reported. So，the accurate determination of Curie temperature is conducive to reconsider the inhomogeneous chiral-spin state and reconstruct the magnetic phase diagram in the precursor region of helimagnet FeG.

L. Xu, H. Han, J. Fan, D. Shi, D. Hu, H. Du, L. Zhang, Y. Zhang and H. Yang, Magnetic entropy change and accurate determination of Curie temperature in single-crystalline helimagnet FeGe, EPL 117, 47004 (2017)
[Abstract]