Magnetoelectric surface acoustic wave resonator with ultrahigh magnetic   field sensitivity
  A magnetoelectric surface acoustic wave (MESAW) type device based on piezoelectric/magnetostrictive heterostructure was proposed to use as weak magnetic field sensor. Unlike conventional magnetoelectric bulk laminates or film stacks collecting magnetic field induced electrical charge, the MESAW detects the shift of the center frequency, which highly depends on the magnetic field due to the giant delta E effect and the phase velocity dispersion. The magnetic field sensitivity can reach 10^(-11) Tesla in consideration of 100 Hz frequency accuracy. Additionally, the unique working mechanism of MESAW allows a broadband detection of weak magnetic field even with no bias magnetic field. 
Liang Huang, Dandan Wen, Zhiyong Zhong, Huaiwu Zhang and Feiming Bai
cond-mat.mtrl-sci