Ferromagnetic Definition and 76 Threads

Hi, I know, not another one, but I'm a more practical/engineering than scientific type - I need some tangible thing to learn stuff, so bear with me :) Let me say hello first :) The general idea was to model movement and electrical stuff with diff equations and do the hard part with femm. The...

Why is this stainless steel ferromagnetic while that one is non/paramagnetic, how's each proportion of them and what's its key difference that'd determines such the distinction?

Hello all! I have a earring project with magnets involved but no magnet expert involved :( Here are a few stupid questions I hope someone can help us with! BACKGROUND: We are designing magnetic earrings. The earrings are meant to clamp the ear with 3 different levels of pressure. The magnetic...

I have thought about the following ##\oint \vec{H}\cdot d\vec{l}=0\Leftrightarrow H_{int}(D-h)+H_{ext}h=0\Leftrightarrow (\frac{B}{\mu_0}-M)(D-h)+\frac{B}{\mu_0}h=0\Leftrightarrow M=\frac{D}{D-h}\frac{B}{\mu_0}## but (supposing what I have done is correct) I don't understand which value of ##B##...

How do we magnetize a ferromagnetic material the best, easiest way, e.g., can we just let it sit around strong magnets in a particular position?

Hellooo I have another questions about that fact that we have only a few solids that are ferromagnetic. In ferromagnetics i also read a few time ago it is important to consider 2 things about the reason why there is no magnetizaion. And i don't really understand both reasons, so i hope you can...

Homework Statement A long straight cylinder with radius ##a## and length ##L## has an uniform magnetization ##M## along its axis. (a) Show that when its flat extreme is placed on a flat surface with infinite permeability (i.e. a ferromagnet), it adheres with a force equal to: $$F=8\pi a^2 L...

As one know, the force on mangnetic dipole in magnetic field is $$ \vec F = (\vec p_m\cdot \nabla) \vec B_0$$, where B_0 -- external field. Let consider a some magnetic matherial with permeability \mu. The magnetization of matherial is $$M = (\mu - 1) H$$ (in SI units) and by deffinition $$M =...

A complete table of the ac susceptibility ## \chi_m ## of various ferromagnetic materials, where ## M=\chi_m H ##, is something that I have had trouble finding in a google of ferromagnetic materials. In what I have been able to come up with to date, there is quite a spread in the values of...

Hi Everyone - I have a classical E&M physics problem that I've been tearing my hair out over. It relates to how ferromagnetic materials boost the field strength of a non-uniform magnetic field. My takeaway from college physics class was that (assuming there's no saturation in the material) the...

I am creating a product that incorporates magnetic sensing of magnetic nanoparticles. However due to their cost, I have decided to search for other avenues of testing. My question is about whether Iron Powder will retain a magnetic field once magnetized. I basically will place some iron powder...

Hello everyone! I want to know how to compute the force applied on ferrous inside a non-uniform magnetic field, to make it easier, let's assume that the field direction is constant, and the magnitude decreases linearly. Now, I know that ferromagnetic material inside a magnetic field will...

Hi people, In my college laboratory we were assigned an experiment to measure the hysteresis curves of a certain ferromagnetic material at different temperatures. Sounds simple, right? Well, the block of Monel 400 we chose did something weird. We cooled it down to about -200°C and set about to...

Homework Statement There are several parts to this question, however I could complete these parts. It is just an equation used in the prior part to the question that is need to solve this: If we define \begin{equation} \sigma_{n}^{-}=\sigma_{n}^{x}+i\sigma_{n}^{y} \end{equation} and with the...

Homework Statement We have a very long ferromagnetic cylinder with square cross section, with side length a. Cylinder is homogeneosly magnetized over his volume so that the magnetization vector is parallel to the axis of cylinder. Cylinder is in vacuum. Find the current appeared in the cylinder...

Curie temperature for magnetite is 858 C, for iron 1043 C. Duralumin melting point is about 630 C. Does this mean that if I take a small silicone mold, place a magnet underneath it, add ferromagnetic powder to the mold and then pour molten aluminum in, I will get the aluminum detail with...

Now after applying and removal magnetic field H=0 there will be residual magnetic domain in XYZ directions Is the Heisenberg Model at very low temperature express about the energy of the system with higher accuracy than Ising Model in the previous case ? and at high temperature is the Ising...

Homework Statement The following coil-wound core (core length = L , Gap length = lg, cross- sectional area = A , core permeability = only hysteresis graph is given, N = N turns) is driven by a Voltage source, is known that the current in the coil is 60hz AC. Determine...

Hi, I've been thinking about how to calculate a permeability curve, I thought this would be an easy to find online but unfortunately I haven't had any luck. From what I can graphically see below: It appears to me that mu for a ferromagnetic material is proportional to the derivative of B vs H...

Hello! I am trying to understand a few properties of the ferromagnetic powder.I could not get the answers to these questions on the web, since any kind of phrasing i used, popped up search results that related to iron powder or ferromagnetic powder, which are manipulated and shape-shift using...

Hello everyone from the Physics Forums, I'm doing a school project and I'm looking for a potential anode alloy that is ferromagnetic which I could use with a copper cathode. I'm making a battery and I have to use copper as my cathode mainly because I have made the cathode cells structured...

Hello everyone. I'm not entirely sure if this is the right section to post this question in but if it isn't, then I apologize. I'm studying for a test in E&M and I've come across a topic that had me thinking and I'm not quite sure if the explanation I'm thinking of is entirely true. Please...

Why do magnets attract ferromagnetic materials only? Why not other materials as well?

What makes Fe, Co and Ni ferromagnetic compared to all other metals (with exception of Gd, Dy and some exotic alloys according to Wikipedia)? If other ferromagnetic metals just have lower Curie temperatures then why is it so? Sub-question: In pure metals is there any correlation in magnetic...

I have came up with a theory, it could be completely wrong or not but i had the idea of ferromagnetic decomposition and what i mean by this is breaking a ferromagnetic object apart (such as iron) using magnetism. Is this possible or not?

I am reading the book "Lecture notes on Electron Correlation and Magnetism" by Patrik Fazekas. It says, "The ground state (of Heisenberg FM model) is not unique. We have just found that the system has the maximum value of the total spin Stot = LS. Sztot = LS state which is maximally...

What is ferromagetic memories ? I need matter on this help me please, searching so many webs can't get proper matter :(

Hi, My interest in physics is relatively new and recently I've been trying to figure out the answer to what is probably a simple question. Here it is; if one is using an AC EMF meter to read the time varying current from a man-made electromagnetic field, will brandishing ferromagnetic...

Hello. What oscillating field strength, in tesla, is required to cause the magnetization vector of a ferromagnetic material to precess with a fairly large angle at its resonance frequency? I can't find this number anywhere!

Hi, I am doing my PG. To select a topic for my mini project, I select the topic "Ferromagnetic thin films" Probably I will be covering it's properties, fabrication and applications at some basic level. So what is the problem is I have no one to guide me here as I am far away from the...

Hi, I am doing my PG. To select a topic for my mini project, I select the topic "Ferromagnetic thin films" Probably I will be covering it's properties, fabrication and applications at some basic level. So what is the problem is I have no one to guide me here as I am far away from the college...

Homework Statement Electrons in a ferromagnet whose spins are oriented in the direction of, or opposite to, the internal magnetisation carry independent currents I+ and I−. This leads to the material behaving as though it has different conductivity σ+ and σ− for each of the two current...

Hello... I have a question: Physically why when a ferromagnetic is saturated the current is non-sinusoidal ( I'm taking the example of the magnetising current of a transformer). I know graphically and mathemeticalty why( from the hysteresis loop) but In reality what happens(I'm talking about...

I do not understand why ferromagnetic materials are more easily heated by an induction oven than a non/low ferromagnetic material such as copper or aluminum. Are Eddy currents more easily induced into a ferromagnetic material than a conductor lacking a high ferromagnetic property? Why is it so?

Homework Statement Calculate the spin wave dispersion relation Ek for the ferromagnetic Heisenberg model with jtot = 1/2 Assume a 1d square lattice and interactions of strength J between nearest neighbours and zero elsewhere Homework Equations H|k> = [E0 +2jtot\sum J(r)(1-Exp(ik.r) ]...

Homework Statement This isn't exactly a homework question so there aren't any data/numbers to work with. I just want to know what to do if there are two ferromagnetic cores inside a coil of wire, arranged as concentric cylinders. Or how to account for the air gap between the core and the coil...

Considering a bar of ferromagnetic (FM) material (eg, Nickel) placed in a uniform magnetic field (eg, B = 1kG along x). I know the H field produced by a given magnetization M of the ferromagnet (ie, I have \vec{H}=M \cdot \vec{\alpha} for a calculated alpha). How do I determine the total...

Hello. I know very few things about solid state physics, so my question is very basic.. I'm just searching for a clue.. Have some of you ever heard about, or imagine a way, of decreasing the permeability of a ferromagnetic material? Not by raising temperature, but with electric field or...

Homework Statement Given a toroidal core, with known μr, minor radius R1, major radius R2, height h (the section is not a circle, but a rectangle (R2-R1)×h), placed in a magnetic field B0 with cylindrical axisymmetries (B0r=0, B0θ=0, B0z=B0), find the magnetic field resulting by the...

What is the spin direction of the electrons through the ferromagnetic material? It will become parallel or antiparallel? I was confused because the scattering rate and conductivity both depend on the density of state at Fermi level. For ferromagnetic material, is it right to say that at the...

From another thread I think I understand that ferromagnetic material can exist any time, but dia & para magnetic materials exist only when there is an external field. My overview is Macroscopically ferro materials have to align their domains & can remain aligned when field is removed...

Dear All, I have a paramagnetic material, its magnetic moment will saturate at magnetic field of 30 T (all spins align in the field direction). So shall I treat the high field phase as a ferromagnetic phase when I do electronic calculations?

Hello, I'm building a coilgun and I'm confused. I understand that within a solenoid, the magnetic field is homogeneous. I've also read that a ferromagnetic projectile in a coilgun is sucked to the center of the coil. If the magnetic field is the same everywhere through the coil, what is...

Homework Statement Consider an electron gas of density n_{0} in three dimensions that is completely ferromagnetic: all electron spins point in the same direction. Derive: a) The Fermi wave vector in terms of n_{0}. b) The parameter r as the radius in atomic unites that encloses one unit of...

What is the effect of inserting any ferromagnetic, diamagnetic etc in magnetic field?? let me say there is a solenoid of turns per unit length n.magnetic field inside the solenoid will ~μnI. what will happen if an ferromagnetic substance like iron is inserted. How will it effect the magnetic...

For a ferromagnetic material in the hysteresis loop, when increasing field from H=Hc, its magnetization (M) will saturate. But if we decrease field instead, will M decreases clockwise according to the loop? How can we make the ferromagnetic material back into the initial state (H=0, M=0)...

all i can find on the internet are the attractive and repulsive forces between 2 magnets... where can i find the relationship between distance and attractive force , between a magnet and i.e. a piece of iron?

Homework Statement A toroidal shaped magnetic material of radius, a, and cross sectional radius R has a small transverse gap cut into it of length l. The toroid is uniformly overwound with a coil of N loops carrying a current I. Show that for a ferromagnetic material the field in the gap is...

Hi, I have searched the web for a graph that shows the ferromagnetic properties of a metal like iron or nickel as they warms up to the Curie temperature - when the metals becomes non-ferromagnetic. I cannot find any good images or graphs that shows this very clear. I have been told that the...

Consider a brick-shaped ferromagnetic of relative magnetic permeability µ >> 1, which has dimensions 2a × 2a × a and a narrow slit of width d and depth a sawed into it as shown in Figure. You may assume that µd >> a >> d. A circular loop of diameter a and inductance L, made of a superconducting...