Abstract
Two-dimensional artificial magnetic honeycomb lattice is predicted to manifest thermodynamic phase transition to the spin solid order ground state at low temperature. Nonlinear susceptibilities are very sensitive to thermodynamic phase transition. We have performed the analysis of nonlinear susceptibility to explore the thermodynamic nature of spin solid phase transition in artificial honeycomb lattice of ultra-small connected permalloy (Ni$_{0.81}$Fe$_{0.19}$) elements, typical length of $\simeq$ 12 nm. The nonlinear susceptibility, $\chi_{n1}$, is found to exhibit an unusual cross-over character in both temperature and magnetic field. The higher order susceptibility $\chi_3$ changes from positive to negative as the system traverses through the spin solid phase transition at $T_s$ = 29 K. Additionally, the static critical exponents, used to test the scaling of $\chi_{n1}$, do not follow the conventional scaling relation. We conclude that the transition to the ground state is not truly thermodynamic, thus raises doubt about the validity of predicted zero entropy state in the spin solid phase.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.