Reducing the equivalent magnetic noise of Metglas/Mn-PMNT laminate composites via annealing treatment

•Annealing treatment contribute to reduce the dielectric loss of Mn-PMNT.•Activation energy and dc conductivity change with oxygen vacancies concentration.•Theoretical and experimental studies show that annealing treatment can reduce EMN. The variation of dielectric loss in [1 1 0] -oriented Mn-doped 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (Mn-PMNT) single crystals after different annealing treatments, as well as their influence on equivalent magnetic noise (EMN) for magnetoelectric laminate composites, were investigated in this study. Dielectric loss can be reduced significantly in oxygen-sufficient atmosphere and high annealing temperature, and dielectric constant varies little in this annealing process, which is favorable to the decrease of the dielectric loss noise. The temperature dependence of dc conductivity was used to characterize the change of dc conductivity and activation energy, which indicated that oxygen vacancies in Mn-PMNT single crystals can be reduced by the annealing treatment, leading to the decrease of dielectric loss. For the influence of magnetoelectric laminate composites, the EMN is clearly reduced in low frequency range (10