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Ta/NiFe/nonmagnetic metal spacer/FeMn films were prepared by magnetron sputtering. The dependences of the exchange coupling field (Hex) between an antiferromagnetic FeMn layer and a ferromagnetic NiFe layer on the thickness of nonmagnetic metal spacer layers were system-atically studied. The results show that the Hex dramatically decreases with the increase in the thicknesses of Bi and Ag spacer layers. However, it gradually decreases with the increase in the thickness of a Cu spacer layer. For a Cu space layer, its crystalline structure is the same as that of NiFe and the lattice parameters of them are close to each other. The Cu layer and FeMn layer will epitaxially grow on the NiFe layer in succession, so the (111) texture of the FeMn layer will not be damaged. As a result, the Hex gradually decreases with the deposition thickness of a Cu layer. For an Ag space layer, its crystalline structure is the same as that of NiFe, but its lattice parameter is very different from that of NiFe. Thus, neither an Ag nor an FeMn layer will epitaxially grow on the NiFe layer and the (111) texture of the FeMn layer will be damaged. The Hex rapidly decreases with the increase in the deposition thickness of an Ag layer. For a Bi spacer layer, not only its crystalline structure but also its lattice parameter is greatly different from that of NiFe. For the same reason, the Bi and FeMn layer cannot epitaxially grow on the NiFe layer. The texture of the FeMn layer will also be damaged. Therefore, the Hex rapidly decreases with the increase in the deposition thick-ness of a Bi layer as well. However, the research result of X-ray photoelectron spectroscopy indi-cates that a very small amount of surfactant Bi atoms will migrate to the FeMn layer surface when they are deposited on the NiFe/FeMn interface. Thus, the Hex will hardly decrease.
Ta / NiFe / nonmagnetic metal spacer / FeMn films were prepared by magnetron sputtering. The dependences of the exchange coupling field (Hex) between an antiferromagnetic FeMn layer and a ferromagnetic NiFe layer on the thickness of nonmagnetic metal spacer layers were system-atically studied. The results show that the six significant steps with the increase in the thicknesses of Bi and Ag spacer layers. However, it gradually decreases with the increase in the thickness of a Cu spacer layer. as that of NiFe and the lattice parameters of them are close to each other. The Cu layer and FeMn layer will epitaxially grow on the NiFe layer in succession, so the (111) texture of the FeMn layer will not be damaged. , the Hex 6b gradually decreases with the deposition thickness of a Cu layer. For an Ag space layer, whose crystalline structure is the same as that of NiFe, but its lattice parameter is very different from that of NiFe Thus, neither an Ag nor an FeMn layer will epitaxially grow on the NiFe layer and the (111) texture of the FeMn layer will be damaged. The Hex rapidly decreases in the deposition thickness of an Ag layer. For a Bi spacer layer, not only its crystalline structure but also its lattice parameter is greatly different from that of NiFe. For the same reason, the Bi and FeMn layer can not epitaxially grow on the NiFe layer. The texture of the FeMn layer will also be damaged. However, the research result of X-ray photoelectron spectroscopy indi-cates that a very small amount of surfactant Bi atoms will migrate to the FeMn layer surface when they are deposited on the NiFe / FeMn interface. Thus, the Hex will hardly decrease.