Novel exchange-spring configuration for excellent magnetic and magnetostrictive softness

Magnetization and magnetostriction data are reported for discontinuous type exchange-spring Tb(Fe0.55Co0.45)1.5/(Y0.1Fe0.9) multilayers, in which nanograins coexist with amorphous phase in soft YFe layers. This novel exchange-spring configuration exhibits an excellent magnetic and magnetostrictive softness: low magnetic coercivity (μ0HC=1mT), large magnetostriction (λγ,2=720×10-6) and large parallel magnetostrictive susceptibility (χλ||=dλ||/dμ0H=29.7×10-2T-1). In addition, the observed phenomena of the negative contribution to magnetostriction, the formation of the extended domain wall at the interfaces and the exchange-bias are discussed.