System Maintenance:
There may be intermittent impact on performance while updates are in progress. We apologize for the inconvenience.
By Topic

Magnetics, IEEE Transactions on

Issue 3 • Date May 1985

Filter Results

Displaying Results 1 - 13 of 13
  • [Front cover and table of contents]

    Publication Year: 1985 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (300 KB)  
    Freely Available from IEEE
  • The next decade in magnetic recording

    Publication Year: 1985 , Page(s): 1217 - 1220
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (408 KB)  

    Experimental data are given on the recording performance of several modern magnetic recording materials. On the basis that the signal to reproduce head noise will prove to be the eventual limit, estimates of the attainable recording densities are made. Areal densities of several hundred megabits per square inch are forecast. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Demagnetization-free longitudinal recording on flexible thin film metal media

    Publication Year: 1985 , Page(s): 1221 - 1227
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (632 KB)  

    The variation of demagnetization effects with media parameters for longitudinal contact recording has been investigated. Co-Re thin film metal media were sputtered onto flexible polyimide substrates. It was found that when the film thickness δ and demagnetizaton parameter B_{r}\delta /H_{c} were less than 2 μ inch and 15 μinch, respectively, demagnetization-free longitudinal recording was obtained up to the recording density of 75 KFRPI at the head-to-medium spacing of 3 μ inch. As a result, recording densities of D50over 50 KFRPI were achieved with a 20 μinch gap head. For thicker films with larger demagnetization parameters, i.e., \delta \geq 4 \mu inch and B_{r}\delta /H_{c} \geq 40 \mu inch, the longitudinal recording process approached the demagnetization limit. The results show that (with existing head field gradients) improvement in linear density of thin metal media can be obtained by an approximate factor of two before the demagnetization limit is reached. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An extended scheme of magnetic-bubble electronic dictionary

    Publication Year: 1985 , Page(s): 1228 - 1234
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (704 KB)  

    A scheme to incorporate input/output of simplified Chinese characters and phonetic Chinese into an electronic dictionary is described. Allowable search keys include HCH codes for ordinary Chinese characters, HCH codes for simplified Chinese characters, Chinese phonetic codes, Universal Words, and English and French words. The dictionary look-up can be done by specifying part of the key content. A microprocessor-based prototype has been cohstructed to demonstrate the scheme using magnetic bubble memory. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Simple boundary element method for three-dimensional magnetostatic problems

    Publication Year: 1985 , Page(s): 1235 - 1239
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (560 KB)  

    For numerical solution of three-dimensional magnetostatic problems the applications of finite-difference (FDM) and finite-element (FEM) methods require long calculating time and large storage capacity. In some cases these requirements can be reduced by the use of boundary element methods (BEM). A simple boundary element solution, and its application to the calculation of magnetization and stray fields of magnetic bodies, is described. The results are compared with experimental stray-field measurements performed using a vibrating pick-up loop magnetometer with high geometrical resolution [14]. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Difference between temperature dependences of both initial permeability and maximum permeability of sendust alloys

    Publication Year: 1985 , Page(s): 1240 - 1244
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (392 KB)  

    The temperature dependences (-10-50°) of the initial permeability (μ5), the maximum permeability (μmax), and the coercive force(Hc) of Sendust alloys (Fe-9 to 10 wt% Si-5 to 7 wt% Al) continuously cooled to room temperature, were investigated. Most of the studied alloys gave at least one peak value for both μ5and μmax, in the studied temperature range. The temperature giving the peak μ5agreed well with that of μmax(an effective permeability at an alternating field): the peak temperature of μeffseems to correspond to the temperature giving a zero magnetocrystalline anisotropy constant (K1= 0). The relationship between temperature and μ5was not always the same as that between temperature and μmax. From the compositional dependence of μmaxat various temperatures (10-30°C), the zero polycrystalline magnetostriction constant (λs = 0) line of the ternary Sendust alloys at each temperature could be evaluated. It is clarified that μ5of the alloys with K1< 0 is determined by both K1and λs, whereas μmaxis primarily determined by λs. When K1changes with temperature from a negative to a positive value, both μ5and μmaxof the alloys markedly decrease, independently of λs. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Au-Fe-Ni permanent magnet alloys

    Publication Year: 1985 , Page(s): 1245 - 1249
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (736 KB)  

    A gold permanent magnet for an ornamental material is developed in the Au-Fe-Ni system. It is found that the magnetic properties of the An-12.5 wt% Fe-12.5 wt% Ni alloy aged at 450°C for seven hours and cold-swaged by 92 percent are Br = 0.53 T (5300 G), iHc = 40.8 kA/m (510 Oe), and (BH)max = 9.1 kJ/m3(1.1 MGOe). The Au-12.5 wt% Fe-10 wt% Ni-2.5 wt% Co alloy aged at 450°C for 2.5 h and swaged by 86 percent attained Br = 0.54 T (5400 G), iHc = 42.4 kA/m (530 Oe), and (BH)max = 9.6 kJ/m3(1.2 MGOe). In these alloys, the magnetic hardening is due to the fine Fe-Ni rich ferromagnetic particles precipitated in the Au matrix. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Electromagnetic braking of a metallic projectile in flight

    Publication Year: 1985 , Page(s): 1250 - 1253
    Cited by:  Papers (4)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (344 KB)  

    A simple model for the electromagnetic deceleration of a moving metallic projectile is described. It incorporates the influence of magnetic field parameters, time-dependent field diffusion, and device geometry on braking action, albeit in an approximate fashion. The model predicts that a viable experimental braking device can be designed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multipole analysis of biomagnetic signals from the human leg

    Publication Year: 1985 , Page(s): 1254 - 1261
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (792 KB)  

    Computationally tractable solutions of the "inverse problem," the calculation of source currents from magnetic field data, are an essential component of biomagnetic studies. A multipole analysis suitable for any system that may be modeled as having all currents oriented along a given axis but not depending on the value of position coordinate on that axis is described. The lowest nonvanishing term is dipolar, and we specify a "best fit" criterion that estimates from data the dipole's magnitude and orientation together with its location in the transverse plane. The dipolar term is seen to give good fits to fields measured outside the normal relaxed lower human leg, even though the field data varies with position along the leg-axis. Reasons for this success are considered. The analysis is not specific to biomagnetic systems and may be useful in electrical engineering or geophysical problems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Iron saturation effects in PM AC motors

    Publication Year: 1985 , Page(s): 1262 - 1265
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (336 KB)  

    Iron saturation causes the lumped circuit parameters to vary with the point of operation. Experimental evidence shows that the field excitation voltage and the direct axis reactance are not affected significantly by the armature reaction. This can be attributed to the presence in the direct axis of the magnets whose thickness represents a large effective air gap. In the quadrature axis, instead, the contribution of the air gap to the reluctance is small. Therefore, the quadrature axis reactance depends strongly on both the quadrature and direct axis components of armature magnetomotive force. This suggests a simple, albeit approximate, approach for predicting the parameter variation with operating point. As a result, both the design and analysis of synchronous motors excited by permanent magnets (PM's) are facilitated. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Active power loss in thin nonmagnetic tape generated by two-sided inductor heater

    Publication Year: 1985 , Page(s): 1266 - 1270
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB)  

    A method for calculating eddy current losses that are produced in thin nonmagnetic tape and generated by a two-sided induction heater is presented. The integral equation method permits an approximate solution of the problem. The distribution of the current density and the active power loss in the tape are considered. It is shown that the integral equation method is more useful to analysis of the system with a big flux dissipation than the finite element method. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • [Back cover]

    Publication Year: 1985 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (1270 KB)  
    Freely Available from IEEE
  • Determination of anisotropy parameters in magnetically uniaxial specimens by torque derivatives

    Publication Year: 1985 , Page(s): 1271 - 1273
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB)  

    Formulae are given for determination, from torque curve slopes, of the first- and second-order anisotropy parameters in magnetically uniaxial specimens. The customary situation in which torque is plotted versus applied magnetic field orientation angle is examined. Corrections to measured torque slope arise from the off-set of the magnetization vector \over\rightarrow{M}_{s} , from the applied magnetic field \over\rightarrow{H} direction. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

IEEE Transactions on Magnetics publishes research in science and technology related to the basic physics and engineering of magnetism, magnetic materials, applied magnetics, magnetic devices, and magnetic data storage.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Pavel Kabos
National Institute of Standards and Technology