FePt （50 nm） and [FePt（a nm）/MgO（b nm）5/glass （a=1, 2, 3; b=1, 2, 3） films were prepared by radio frequency （RF） magnetron sputtering technique, and then were annealed at 600℃ for 30 min. The effect of MgO ...FePt （50 nm） and [FePt（a nm）/MgO（b nm）5/glass （a=1, 2, 3; b=1, 2, 3） films were prepared by radio frequency （RF） magnetron sputtering technique, and then were annealed at 600℃ for 30 min. The effect of MgO layer thickness on the structures and magnetic properties of the FePt/MgO multilayers was investigated. The coercivities and inter-grain interactions of the FePt/MgO films were decreased, yet the degree of （001） texturing drastically increased with the increase in MgO layer thickness when the FePt layer thickness was fixed. Thus, the FePt/MgO films with appropriate coercivities, high perpendicular anisotropy, and weak intergrain interactions were obtained by controlling the MgO layer thickness. Overall, these results indicate that the FePt/MgO nanostructured films are promising candidates for future high-density perpendicular recording media.展开更多
The amorphous CoZr soft magnetic films with superior properties were prepared by radio-frequency sputtering under pressure of 0.5Pa Ar.The saturation magnetization of the amorphous CoZr films with relation to the Zr c...The amorphous CoZr soft magnetic films with superior properties were prepared by radio-frequency sputtering under pressure of 0.5Pa Ar.The saturation magnetization of the amorphous CoZr films with relation to the Zr content and temperature was investigated.The amorphous CoZr films composed of different constituents obey the Bloch T^(3/2)-low in a wide range of temperatures.The number of electrons transferred from each Zr atom to 3d energy band of Co calculated by the rigid band model is about 2.27.展开更多
（Pt/Co）n/FeMn multilayers with perpendicular anisotropy （PA） were prepared by magnetron sputtering with Pt as the buffer layer and the capping layer. The dependence of perpendicular exchange bias （PEB）, Hex, on ...（Pt/Co）n/FeMn multilayers with perpendicular anisotropy （PA） were prepared by magnetron sputtering with Pt as the buffer layer and the capping layer. The dependence of perpendicular exchange bias （PEB）, Hex, on the thickness of the FeMn anfiferromagnet （AFM） layer is similar to that of in-plane exchange bias. The value of Hex for the （Pt/Co）3/FeMn multilayer reaches 22.3 kA/m. A thin Pt spacer was inserted between the Co/FeMn interface to enhance PEB. The PEB reaches the largest at 39.8 kA/m when the thickness of the Pt spacer is 0.4 nm.展开更多
Owing to the epitaxial inducement of Au atom,Au interlayer was introduced to increase the perpendicular anisotropy and the coercivity in L10-FePt nanocomposite film.Micromagnetics can be used to reveal the relationshi...Owing to the epitaxial inducement of Au atom,Au interlayer was introduced to increase the perpendicular anisotropy and the coercivity in L10-FePt nanocomposite film.Micromagnetics can be used to reveal the relationship between microstructure and magnetic properties of materials,and give the information of the perpendicular anisotropy and coercivity.In this work,the effect of the Au interlayer on annealed[Fe（0.5 nm）/Pt（0.5 nm）/Au（d nm）]10 nanocomposite recording medium by a micromagnetic model was studied.The model contains three phases：hard magnetic phase,soft magnetic phase,and nonmagnetic phase.The calculated result shows that perpendicular orientation degree of the texture and proportion of a hard magnetic phase to the total phase in the annealed film are both enhanced by increasing Au interlayer thickness.This result can be conducive to the improvement of the perpendicular anisotropy and the coercivity of the FePt nanocomposite film in the experiments.展开更多
The magnetic force microscopy and a sample vibrating magnetometer have been used to investigate the domain structure in two antiferromagnetically coupled Co/Pt multilayers.In the antiferromagnetic coupled[Pt（0.5 nm）...The magnetic force microscopy and a sample vibrating magnetometer have been used to investigate the domain structure in two antiferromagnetically coupled Co/Pt multilayers.In the antiferromagnetic coupled[Pt（0.5 nm）/Co（0.4 nm）]n/NiO（1.1 nm）/[Co（0.4 nm）/Pt（0.5 nm）]n multilayers with perpendicular anisotropy,the antiferromagnetic interlayer coupling strength increases linearly with the repetition number n in Co/Pt multilayers.In demagnetized states,relatively shifted domain walls in the two Co/Pt multilayers are observed,with net ferromagnetic stripes formed between them for the repetition number n less than 5,and the stripe width decreases with the increase of n.The occurrence of these features can be attributed to the competition between the interlayer coupling and magnetostatic energies.展开更多
[Tb/Fe/Dy]n nano-multilayer films, with precise composition of Tb0.27Dy0.73Fe2, were prepared by the multi-targets magnetron sputtering technique at room temperature (sample A) and 300℃ substrate temperature (sample ...[Tb/Fe/Dy]n nano-multilayer films, with precise composition of Tb0.27Dy0.73Fe2, were prepared by the multi-targets magnetron sputtering technique at room temperature (sample A) and 300℃ substrate temperature (sample B). Both of the nano-multilayer films show columnar structures perpendicular to the film plane according to the scanning electron microscopy results. The magnetic hysteresis loops and the giant magnetostriction (GMS) property of the two samples indicate the perpendicular anisotropy in them. In spite of the perpendicular anisotropy, both of the samples present GMS effect. In a very low applied field of 0.18 T, the GMS value in sample B is 89.3 ppm, which is about four times of that in sample A, 23.5 ppm. The good low-field GMS effect in sample B might attribute to the Laves phase of R-Fe2 segregated from the amorphous matrix under the thermal annealing of the substrate. The relation between the magnetization process and GMS property of the perpendicular anisotropy nano-multilayer films is further investigated.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No.10574085)the Opening Foundation of the Key Laboratory of Shanxi Province (200503010)the Key Project of the Ministry of Education of China (No.207020).
文摘FePt （50 nm） and [FePt（a nm）/MgO（b nm）5/glass （a=1, 2, 3; b=1, 2, 3） films were prepared by radio frequency （RF） magnetron sputtering technique, and then were annealed at 600℃ for 30 min. The effect of MgO layer thickness on the structures and magnetic properties of the FePt/MgO multilayers was investigated. The coercivities and inter-grain interactions of the FePt/MgO films were decreased, yet the degree of （001） texturing drastically increased with the increase in MgO layer thickness when the FePt layer thickness was fixed. Thus, the FePt/MgO films with appropriate coercivities, high perpendicular anisotropy, and weak intergrain interactions were obtained by controlling the MgO layer thickness. Overall, these results indicate that the FePt/MgO nanostructured films are promising candidates for future high-density perpendicular recording media.
文摘The amorphous CoZr soft magnetic films with superior properties were prepared by radio-frequency sputtering under pressure of 0.5Pa Ar.The saturation magnetization of the amorphous CoZr films with relation to the Zr content and temperature was investigated.The amorphous CoZr films composed of different constituents obey the Bloch T^(3/2)-low in a wide range of temperatures.The number of electrons transferred from each Zr atom to 3d energy band of Co calculated by the rigid band model is about 2.27.
基金This work was financially supported by the National Natural Science Foundation of China (No.50471093)the Science Founda-tion of Beijing (No.2052014)
文摘（Pt/Co）n/FeMn multilayers with perpendicular anisotropy （PA） were prepared by magnetron sputtering with Pt as the buffer layer and the capping layer. The dependence of perpendicular exchange bias （PEB）, Hex, on the thickness of the FeMn anfiferromagnet （AFM） layer is similar to that of in-plane exchange bias. The value of Hex for the （Pt/Co）3/FeMn multilayer reaches 22.3 kA/m. A thin Pt spacer was inserted between the Co/FeMn interface to enhance PEB. The PEB reaches the largest at 39.8 kA/m when the thickness of the Pt spacer is 0.4 nm.
基金financially supported by the National Natural Science Foundation of China (Nos.61227902, 11274033, and 11074101)
文摘Owing to the epitaxial inducement of Au atom,Au interlayer was introduced to increase the perpendicular anisotropy and the coercivity in L10-FePt nanocomposite film.Micromagnetics can be used to reveal the relationship between microstructure and magnetic properties of materials,and give the information of the perpendicular anisotropy and coercivity.In this work,the effect of the Au interlayer on annealed[Fe（0.5 nm）/Pt（0.5 nm）/Au（d nm）]10 nanocomposite recording medium by a micromagnetic model was studied.The model contains three phases：hard magnetic phase,soft magnetic phase,and nonmagnetic phase.The calculated result shows that perpendicular orientation degree of the texture and proportion of a hard magnetic phase to the total phase in the annealed film are both enhanced by increasing Au interlayer thickness.This result can be conducive to the improvement of the perpendicular anisotropy and the coercivity of the FePt nanocomposite film in the experiments.
文摘The magnetic force microscopy and a sample vibrating magnetometer have been used to investigate the domain structure in two antiferromagnetically coupled Co/Pt multilayers.In the antiferromagnetic coupled[Pt（0.5 nm）/Co（0.4 nm）]n/NiO（1.1 nm）/[Co（0.4 nm）/Pt（0.5 nm）]n multilayers with perpendicular anisotropy,the antiferromagnetic interlayer coupling strength increases linearly with the repetition number n in Co/Pt multilayers.In demagnetized states,relatively shifted domain walls in the two Co/Pt multilayers are observed,with net ferromagnetic stripes formed between them for the repetition number n less than 5,and the stripe width decreases with the increase of n.The occurrence of these features can be attributed to the competition between the interlayer coupling and magnetostatic energies.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 60477003, 10774046)
文摘[Tb/Fe/Dy]n nano-multilayer films, with precise composition of Tb0.27Dy0.73Fe2, were prepared by the multi-targets magnetron sputtering technique at room temperature (sample A) and 300℃ substrate temperature (sample B). Both of the nano-multilayer films show columnar structures perpendicular to the film plane according to the scanning electron microscopy results. The magnetic hysteresis loops and the giant magnetostriction (GMS) property of the two samples indicate the perpendicular anisotropy in them. In spite of the perpendicular anisotropy, both of the samples present GMS effect. In a very low applied field of 0.18 T, the GMS value in sample B is 89.3 ppm, which is about four times of that in sample A, 23.5 ppm. The good low-field GMS effect in sample B might attribute to the Laves phase of R-Fe2 segregated from the amorphous matrix under the thermal annealing of the substrate. The relation between the magnetization process and GMS property of the perpendicular anisotropy nano-multilayer films is further investigated.
