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Determination of impurity elements in MnZn ferrites by inductively coupled plasma mass spectrometry 被引量:3
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作者 张萍 符靓 +1 位作者 马俊才 唐有根 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第1期37-42,共6页
An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+H... An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water, then the above 16 impurity elements in the solution were analyzed directly by ICP-MS. The impurity elements were introduced by the helium gas or hydrogen gas into the octopole reaction system(ORS) to eliminate the polyatomic interferences caused by the high salty matrixes. The matrix effect was minimized through matrix matching,and Be, Y and Rh were used as internal standard elements. The working parameters of the instrument were optimized. The results show that the method has good precision and high accuracy. The detection limits for the investigated elements are in the range of0.9-37.5 ng/L, the relative standard deviation of each element is within 1.1%-4.8%, and the recovery of each element is 90%-108%. 展开更多
关键词 inductively coupled plasma mass spectrometry(ICP-MS) mnzn ferrites octopole reaction system(ORS) impurity elements
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Effects of Hyperfine and Dopant Cation Interactions on theDC-Electrical Conductivity of MnZn Ferrites
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作者 M.M.Abou Sekkina(Chem. Dept., Faculty of Science, Tanta University, Tanta, Egypt)A.M.El-Sayed(Inorganic Chemistry Dept., National Research Centre, Dokki, Cairo, Egypt) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1997年第6期467-470,共4页
Samples of undoped, and CuO, CaO, Al2O3 as well as V2O5 doped MnZn ferrite were prepared using standard ceramic method. The X-ray diffraction results for the base and doped ferrite samples show a single phase with spi... Samples of undoped, and CuO, CaO, Al2O3 as well as V2O5 doped MnZn ferrite were prepared using standard ceramic method. The X-ray diffraction results for the base and doped ferrite samples show a single phase with spinel cubic structure. The Mossbauer spectrum of the base sample indicates line broadening and overlapping due to relaxation of magnetic dipoles. The temperature dependence of DC-electrical conductivity has been discussed on the basis of electronic conduction (electron hopping) and ionic conduction mechanism. 展开更多
关键词 Effects of Hyperfine and Dopant Cation Interactions on theDC-Electrical Conductivity of mnzn ferrites
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Microstructure and magnetic performance of Ni-substituted high density MnZn ferrite 被引量:3
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作者 YU Zhong LAN Zhongwen +2 位作者 CHEN Shengming SUN Yueming SUN Ke 《Rare Metals》 SCIE EI CAS CSCD 2006年第z1期584-587,共4页
The effects of NiO on microstructure and magnetic properties of Mn-Zn ferrite with a nominal composition of Zn_(0.32)Mn_(0.60-x)Ni_(x)Fe_(2.08)O_(4)were investigated.The calcined powder of Mn-Zn ferrite was characteri... The effects of NiO on microstructure and magnetic properties of Mn-Zn ferrite with a nominal composition of Zn_(0.32)Mn_(0.60-x)Ni_(x)Fe_(2.08)O_(4)were investigated.The calcined powder of Mn-Zn ferrite was characterized by X-ray diffraction(XRD),the fracture surface of Mn-Zn ferrite was checked by scanning electronic microscope(SEM),and then the magnetic properties were measured.As a result,the substitution of Ni can cause the crystal lattice constant of MnZn ferrite to decline,and the grain size to decrease,therefore improve the magnetic performance of MnZn ferrite whose density exceeds 5.0 g·cm^(-3). 展开更多
关键词 mnzn ferrite Ni-substitution MICROSTRUCTURE magnetic performance
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Determination of trace impurity elements in MnZn ferrite powder by direct current glow discharge mass spectrometry 被引量:3
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作者 FU Liang MA Jun-cai SHI Shu-yun 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第7期1590-1597,共8页
An analytical method for the determination of 26 impurity elements (such as Li, Be, Na, Mg, Al, Si, P, S, K, Ca, Sc, Ti, V, Cr, Co, Ni, Ga, Ge, Y, Nb, Mo, Ag, Cd, Sb, W and Pb) in MnZn ferrite powder by direct curre... An analytical method for the determination of 26 impurity elements (such as Li, Be, Na, Mg, Al, Si, P, S, K, Ca, Sc, Ti, V, Cr, Co, Ni, Ga, Ge, Y, Nb, Mo, Ag, Cd, Sb, W and Pb) in MnZn ferrite powder by direct current glow discharge mass spectrometry (GD-MS) was established. MnZn ferrite powder was mixed with copper powder, used as a conductor, and pressed. The effects of MnZn ferrite powder preparation conditions and glow discharge parameters for the sensitivity and stability of signal analysis were investigated. By determining the choice of isotope and the application of the mass resolutions of 4000 (MR, medium resolution) and 10000 (HR, high resolution), mass spectral interference was eliminated. The contents of impurity elements in MnZn ferrite powder was calculated by subtraction after normalizing the total signal of Mn, Zn, Fe, O and Cu. The results showed that the detection limit of 26 kinds of impurity elements was between 0.002 and 0.57 μg/g, and the relative standard deviation (RSD) was between 3.33% and 32.35%. The accuracy of this method was verified by the ICP-MS. The method was simple and practical, which is applied to the determination of impurity elements in MnZn ferrite powder. 展开更多
关键词 mnzn ferrite powder glow discharge mass spectrometry impurity elements copper powder
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Study on sintering process and characteristic of nanosized soft magnetic MnZn ferrite powders 被引量:2
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作者 WANG Yongming WANG Xin JIANG Yanfei HAO Shunli LIU Chunjing 《Rare Metals》 SCIE EI CAS CSCD 2006年第z1期531-535,共5页
The effect of sintering process (especially the sintering temperature) on the magnetic property and microstructure of sintered sample of nanosized soft magnetic MnZn ferrite powder was investigated. The sintered sampl... The effect of sintering process (especially the sintering temperature) on the magnetic property and microstructure of sintered sample of nanosized soft magnetic MnZn ferrite powder was investigated. The sintered sample of MnZn ferrite was prepared by both traditional pressing and cool isostatic pressing on MnZn ferrite nanoparticals. The sintering process of which was segmented. The density, microstructure and phase composition of sintered sample were analyzed by Archimedes′law, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The grain growth and densification in sintering process of MnZn ferrite were investigated. The magnetic property was measured by vibrating sample magnetometer (VSM) and Nim2000 magnetic material testing system. The results show that the better sintering temperature is 850 ℃, at which the better magnetic property and microstructure of sintered compact were obtained. 展开更多
关键词 mnzn ferrite sintering temperature MICROSTRUCTURE magnetic property
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Effects of La^(3+) doping on MnZn ferrite nanoscale particles synthesized by hydrothermal method 被引量:1
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作者 古映莹 谭小平 +1 位作者 梁叔全 桑商斌 《Journal of Central South University of Technology》 2004年第2期166-168,共3页
MnZn ferrite nanoscale particles were synthesized by hydrothermal method. The effects of amount of addition La3+ on the products were discussed. The product was characterized by X-ray diffraction (XRD) and transmiss... MnZn ferrite nanoscale particles were synthesized by hydrothermal method. The effects of amount of addition La3+ on the products were discussed. The product was characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The results show that the sample with 0.2% La3+(mass fraction) or without La3+ has only spinel phase, but the sample with mass fraction of La3+ exceeding 0.4% posses second phase besides the spinel one; and the nano-MnZn ferrites change from cube to hexagon when the mass fractions of La3+ is up to (1.2%.) TEM image of the sample with 1.2% La3+ indicates that the homogeneous hexagonal crystal is obtained and the particles are larger than those of undoped; the addition of La3+ has great influence on the crystallization of hydrothermal process and can change the shape of particles and improve their growth. The saturation magnetization of the sample with 1.2% La3+ (2.64 A·m2·kg-1) is lower than that of undoped (17.54 (A·m2·kg-1)) and it behaves superparamagnetically. 展开更多
关键词 hydrothermal method mnzn ferrite nanoscale particle DOPING
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Preparation and properties of nanosize MnZn ferrite from δ-FeOOH
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作者 HAO Shunli WANG Xin WEI Yu Wang Yongming Liu Chunjing 《Rare Metals》 SCIE EI CAS CSCD 2006年第z1期466-470,共5页
Ferrous ion was transformed into feroxyhyte (δ-FeOOH) by oxidation. Then, manganese sulfate and zinc sulfate in some ratio were added to the feroxyhyte solution. The co-precipitation was boiling reflux conditions som... Ferrous ion was transformed into feroxyhyte (δ-FeOOH) by oxidation. Then, manganese sulfate and zinc sulfate in some ratio were added to the feroxyhyte solution. The co-precipitation was boiling reflux conditions sometime under constant stirring. The nanosize MnZn ferrite powder was formed. The mechanism of preparation of the nanosize MnZn ferrite was discussed, and the formation of feroxyhyte which was playing a key role during the process was mentioned. The properties of powder was tested by means of X-ray diffraction, transmission electron microscopy and vibrating sample magnetometer. The results show that the samples of spherical particles about 20 nm, which have characteristics of ferrimagnetism, has larger saturation magnetization, but the remanent magnetization and coercivity are comparatively smaller. The spinel MnZn ferrite nanosize powder was successfully prepared from δ-FeOOH at low temperature, with low-carbon steel and peroxide as main material. 展开更多
关键词 NANOSIZE mnzn ferrite feroxyhyte PREPARATION CHARACTERIZATION
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Studies on the Relation between the Composition of Thermal Sensitive MnZn Ferrite and Curie Temperature
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作者 Mengkui WANG (Department of Physics, Jinzhou Teachers College, Jinzhou 121003, China) Junyue WANG (Jinzhou Audio-Visual Education Center, Jinzhou 121000, China) Ke SUN (Department of Physics, Northeastern University, Shenyang 110006, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第2期209-210,共2页
Thermal sensitive MnZn ferrite is a kind of soft magnetic ferrite material with lower Curie temperature (Tc) and can be used to make many kinds of magnetic thermal sensitive sensors with high sensitivity. In this pape... Thermal sensitive MnZn ferrite is a kind of soft magnetic ferrite material with lower Curie temperature (Tc) and can be used to make many kinds of magnetic thermal sensitive sensors with high sensitivity. In this paper, the relation between the composition of thermal sensitive ferrite and TC was studied. It was found that TC changes linearly with ZnO extent when the content of Fe2O3 is fixed. Based on lots of experiments, an experimential formula to determine was given out. 展开更多
关键词 Studies on the Relation between the Composition of Thermal Sensitive mnzn Ferrite and Curie Temperature ZnO
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High-frequency MnZn soft magnetic ferrite by engineering grain boundaries with multiple-ion doping 被引量:3
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作者 Mi Yan Shengbo Yi +3 位作者 Xiuyuan Fan Zhenghua Zhang Jiaying Jin Guohua Bai 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第20期165-170,共6页
MnZn soft magnetic ferrites have been widely utilized in power electronics,owing to the combined merits of high permeability and low energy loss.However,their deployment would result in a drastic increase in power dis... MnZn soft magnetic ferrites have been widely utilized in power electronics,owing to the combined merits of high permeability and low energy loss.However,their deployment would result in a drastic increase in power dissipation at>3 MHz,thus limiting the scope extent of miniaturization,together with their efficiency.Here,we report a high-performance MnZn ferrite by doping multiple ions(La,Ti,Si,Ca)at grain boundaries,achieving the most optimized power loss of 267 kW/m^(3) at 5 MHz(10 m T,100℃)and initial permeability of 644,which is much better than the previously reported results and commercial products.Such an improvement is attributed to weakened magnetic exchange coupling at grain-boundary regions,associated with a significant transition from the multi-to mono-domain structures,originating physically from large crystallographic mis-orientations(>25°).The present study bears important significance in understanding the intrinsic correlation between the crystallographic mis-orientation and magnetic domain structure,and provides an alternative way for optimizing high-frequency soft magnetic ferrites. 展开更多
关键词 mnzn ferrite Multi-ion doping MHz application Grain size Crystallographic mis-orientations
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Targeted inductive heating of nanomagnets by a com- bination of alternating current (AC) and static magnetic fields 被引量:3
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作者 Ming Ma Yu Zhang Xuli Shen Jun Xie Yan Li Ning Gu 《Nano Research》 SCIE EI CAS CSCD 2015年第2期600-610,共11页
The conversion of electromagnetic energy into heat by nanomagnets has the potential to be a powerful, non-invasive technique for cancer therapy by hyperthermia and hyperthermia-based drug release, while temperature co... The conversion of electromagnetic energy into heat by nanomagnets has the potential to be a powerful, non-invasive technique for cancer therapy by hyperthermia and hyperthermia-based drug release, while temperature controllability and targeted heating are challenges to developing applications of such magnetic inductive hyperthermia. This study was designed to control the hyperthermia position and area using a combination of alternating current (AC) and a static magnetic field. MnZn ferrite (MZF) nanoparticles which exhibited excellent hyperthermia properties were first prepared and characterized as an inductive heating mediator. We built model static magnetic fields simply using a pair of permanent magnets and studied the static magnetic field distributions by measurements and numerical simulations. The influence of the transverse static magnetic fields on hyperthermia properties was then investigated on MZF magnetic fluid, gel phantoms and SMMC-7721 cells in vitro. The results showed a static magnetic field can inhibit the temperature rise of MZF nanoparticles in an AC magnetic field. But in the uneven static magnetic field formed by a magnet pair with repelling poles face-to-face, the heating area can be restricted in a central low static field; meanwhile the side effects of hyperthermia can be reduced by a surrounding high static field. As a result we can position the hyperthermia area, protect the non-therapeutic area, and reduce the side effects lust by using a well-designed combination of AC and static field. 展开更多
关键词 HYPERTHERMIA magnetic nanoparticles static magnetic field alternating magnetic field mnzn ferrite
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