Properties of exchange interaction in Yb 3Fe 5O 12 under extreme conditions

Abstract

In Yb 3Fe 5O 12, the exchange effective field can be expressed as H eff =− λ· M Fe=− λχ eff · H e =− γ· H e where γ is named as the exchange field parameter and H e is the external magnetic field. Then, in this paper, by the discussions on the characteristics of the exchange field parameter γ, the properties of exchange interaction in ytterbium iron garnet (Yb 3Fe 5O 12) are analyzed under extreme conditions (high magnetic fields and low temperatures). Our theory suggests that the exchange field parameter γ is the function of the temperatures under different external magnetic fields, and γ= a+ b· T+ c· T 2, where the coefficients a, b, c are associated with the external magnetic fields and the magnetized directions. Thus, the temperature-dependence, field-dependence and anisotropic characteristics of the exchange interaction in Yb 3Fe 5O 12 are revealed. Also, excellent fits to the available experiments are obtained.