5.2.3.2 Critical behavior of surface magnetization; live layers

This chapter illustrates critical behavior of surface magnetization and live layers of single crystals. In localized models, the classification of magnetic transitions near surfaces is discussed as a function of the enhancement Δ = (I₁ - I_b)/I_b of exchange interaction in the first monolayer, I₁, in comparison with its value I_b in bulk material. Critical exponents β₁ of first layer magnetization, from theoretical models, is tabulated. Log-log plot of surface layer magnetization m₁ versus reduced temperature (1 - T/T_c) for various ratios of the exchange I_s in surface planes to the exchange I_b in bulk planes, and atomic magnetic moments of simple cubic(100) surface are illustrated. Critical properties of surfaces, from experiments, curie temperature T_{c, s} of the surface in comparison with bulk Curie temperature T_c (Neel temperature T_N) and surface critical exponent β_s of surface magnetization is tabulated. Critical behavior of Ni(100), (110) measured by SPLEED, evidence for live layer of Cr(100) and Gd(0001) and evidence for live layers of Tb(0001) films are figured out.