Thanks to the strong perpendicular magnetic anisotropy(PMA), excellent processing compatibility as well as novel spintronic phenomenon, Co/Pt multilayers have been attracting massive attention and widely used in magne...Thanks to the strong perpendicular magnetic anisotropy(PMA), excellent processing compatibility as well as novel spintronic phenomenon, Co/Pt multilayers have been attracting massive attention and widely used in magnetic storage.However, reversed magnetic domains come into being with the increasing layer repetition ‘N’ to reduce magneto-static energy, resulting in the remarkable diminishment of the remanent magnetization(Mr). As a result, the product of Mrand thickness(i.e., the remanent moment-thickness product, Mrt), a key parameter in magnetic recording for reliable data storing and reading, also decreases dramatically. To overcome this issue, we deposit an ultra-thick granular [Co/Pt]80multilayer with a total thickness of 68 nm on granular SiNxbuffer layer. The Mrt value, Mrto saturation magnetization(Ms) ratio as well as out of plane(OOP) coercivity(Hcoop) are high up to 2.97 memu/cm^(2), 67%, and 1940 Oe(1 Oe = 79.5775 A·m^(-1)),respectively, which is remarkably improved compared with that of continuous [Co/Pt]80multilayers. That is because large amounts of grain boundaries in the granular multilayers can efficiently impede the propagation and expansion of reversed magnetic domains, which is verified by experimental investigations and micromagnetic simulation results. The simulation results also indicate that the value of Mrt, Mr/Msratio, and Hcoopcan be further improved through optimizing the granule size, which can be experimentally realized by manipulating the process parameter of SiNxbuffer layer. This work provides an alternative solution for achieving high Mrt value in ultra-thick Co/Pt multilayers, which is of unneglectable potential in applications of high-density magnetic recording.展开更多
NOx storage and reduction(NSR)technology has been regarded as one of the most promising strategies for the removal of nitric oxides(NOx)from lean-burn engines,and the potential of the plasma catalysis method for NOx r...NOx storage and reduction(NSR)technology has been regarded as one of the most promising strategies for the removal of nitric oxides(NOx)from lean-burn engines,and the potential of the plasma catalysis method for NOx reduction has been confirmed in the past few decades.This work reports the NSR of nitric oxide(NO)by combining non-thermal plasma(NTP)and Co/Pt/Ba/γ-Al2O3(Co/PBA)catalyst using methane as a reductant.The experimental results reveal that the NOx conversion of NSR assisted by NTP is notably enhanced compared to the catalytic efficiency obtained from NSR in the range of 150°C–350°C,and NOx conversion of the 8%Co/PBA catalyst reaches 96.8%at 350°C.Oxygen(O_(2))has a significant effect on the removal of NOx,and the NOx conversion increases firstly and then decreases when the O_(2)concentration ranges from 2%to 10%.Water vapor reduces the NOx storage capacity of Co/PBA catalysts on account of the competition for adsorption sites on the surface of Co/PBA catalysts.There is a negative correlation between sulfur dioxide(SO_(2))and NOx conversion in the NTP system,and the 8%Co/PBA catalyst exhibits higher NOx conversion compared to other catalysts,which shows that Co has a certain SO_(2)resistance.展开更多
Co/Pt multilayers with perpendicular anisotropy were deposited using a dc magnetron sputtering system under high vacuum.Magnetization process was investigated by the measurement of magnetic components parallel and per...Co/Pt multilayers with perpendicular anisotropy were deposited using a dc magnetron sputtering system under high vacuum.Magnetization process was investigated by the measurement of magnetic components parallel and perpendicular to the applied field.A dependence of the coercivity of Co/Pt multilayers on the Co layer thickness was reported,in which the total thickness of Co layers kept constant.It is observed that the coercivity increases with the increment of Co layer thickness.For the samples with the same Co layer thickness while different total Co layer thickness,the coercivity first increases and then decreases with the increase of the total thickness of Co layers.This effect could be attributed to the competition between the reduction of HC related to incoherent reversal and the step-up of HC contributed by the magnetic polarization of Pt atoms at the interface of Co and Pt layers during magnetization reversal.The results show that the change of the coercivity is strongly related to the Co layer thickness,but not the total thickness of Co layers.The dependence of the coercivity on the angle between an applied field and the easy axis shows that the nucleation mode is dominant in magnetization reversal process of the samples.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51901008)the National Key Research and Development Program of China (Grant No. 2021YFB3201800)。
文摘Thanks to the strong perpendicular magnetic anisotropy(PMA), excellent processing compatibility as well as novel spintronic phenomenon, Co/Pt multilayers have been attracting massive attention and widely used in magnetic storage.However, reversed magnetic domains come into being with the increasing layer repetition ‘N’ to reduce magneto-static energy, resulting in the remarkable diminishment of the remanent magnetization(Mr). As a result, the product of Mrand thickness(i.e., the remanent moment-thickness product, Mrt), a key parameter in magnetic recording for reliable data storing and reading, also decreases dramatically. To overcome this issue, we deposit an ultra-thick granular [Co/Pt]80multilayer with a total thickness of 68 nm on granular SiNxbuffer layer. The Mrt value, Mrto saturation magnetization(Ms) ratio as well as out of plane(OOP) coercivity(Hcoop) are high up to 2.97 memu/cm^(2), 67%, and 1940 Oe(1 Oe = 79.5775 A·m^(-1)),respectively, which is remarkably improved compared with that of continuous [Co/Pt]80multilayers. That is because large amounts of grain boundaries in the granular multilayers can efficiently impede the propagation and expansion of reversed magnetic domains, which is verified by experimental investigations and micromagnetic simulation results. The simulation results also indicate that the value of Mrt, Mr/Msratio, and Hcoopcan be further improved through optimizing the granule size, which can be experimentally realized by manipulating the process parameter of SiNxbuffer layer. This work provides an alternative solution for achieving high Mrt value in ultra-thick Co/Pt multilayers, which is of unneglectable potential in applications of high-density magnetic recording.
基金by the National Engineering Laboratory for Mobile Source Emission Control Technology(No.NELMS2019A13)the National Key Research and Development Project of China(No.2019YFC1805505)+2 种基金the Shanxi Province Bidding Project(No.20191101007)the Major Science and Technology Projects of Shanxi Province(No.20181102017)State Key Laboratory of Organic Geochemistry(No.SKLOG-201909)。
文摘NOx storage and reduction(NSR)technology has been regarded as one of the most promising strategies for the removal of nitric oxides(NOx)from lean-burn engines,and the potential of the plasma catalysis method for NOx reduction has been confirmed in the past few decades.This work reports the NSR of nitric oxide(NO)by combining non-thermal plasma(NTP)and Co/Pt/Ba/γ-Al2O3(Co/PBA)catalyst using methane as a reductant.The experimental results reveal that the NOx conversion of NSR assisted by NTP is notably enhanced compared to the catalytic efficiency obtained from NSR in the range of 150°C–350°C,and NOx conversion of the 8%Co/PBA catalyst reaches 96.8%at 350°C.Oxygen(O_(2))has a significant effect on the removal of NOx,and the NOx conversion increases firstly and then decreases when the O_(2)concentration ranges from 2%to 10%.Water vapor reduces the NOx storage capacity of Co/PBA catalysts on account of the competition for adsorption sites on the surface of Co/PBA catalysts.There is a negative correlation between sulfur dioxide(SO_(2))and NOx conversion in the NTP system,and the 8%Co/PBA catalyst exhibits higher NOx conversion compared to other catalysts,which shows that Co has a certain SO_(2)resistance.
基金Projects(10574065,20833002) supported by the National Natural Science Foundation of ChinaProject(2009CB929503) supported by the National Basic Research Program of China
文摘Co/Pt multilayers with perpendicular anisotropy were deposited using a dc magnetron sputtering system under high vacuum.Magnetization process was investigated by the measurement of magnetic components parallel and perpendicular to the applied field.A dependence of the coercivity of Co/Pt multilayers on the Co layer thickness was reported,in which the total thickness of Co layers kept constant.It is observed that the coercivity increases with the increment of Co layer thickness.For the samples with the same Co layer thickness while different total Co layer thickness,the coercivity first increases and then decreases with the increase of the total thickness of Co layers.This effect could be attributed to the competition between the reduction of HC related to incoherent reversal and the step-up of HC contributed by the magnetic polarization of Pt atoms at the interface of Co and Pt layers during magnetization reversal.The results show that the change of the coercivity is strongly related to the Co layer thickness,but not the total thickness of Co layers.The dependence of the coercivity on the angle between an applied field and the easy axis shows that the nucleation mode is dominant in magnetization reversal process of the samples.
基金Project supported by the National Natural Science Foundation of China （Grant Nos.10504019, 10574087）, and the Shanghai Leading Academic Disciplines Program （Grant No.T0104）
文摘铁磁性的回声系列的 Out-of-plane 尖依赖在劈啪作响的公司 / 磅 multilayers 被测量并且与 Landau-Lifshitz-Gilbert 方程分析了。4 蟺 M eff 被发现与减少的 t 磅和减少的 1/t 公司增加的有效消磁领域，它能由于在联合的夹层和低维的效果之间的相互影响被考虑。g 因素与增加 t 磅和减少的 t 公司增加，显示磅原子的纺纱极化的贡献和公司原子的轨道的时刻的另外的贡献。有减少的 t 公司的在里面飞机回声线宽增加和有增加 t 磅的增加。
