What is Magnetic materials: Definition and 17 Discussions

A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets.
A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt and their alloys, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to a magnetic field, by one of several other types of magnetism.
Ferromagnetic materials can be divided into magnetically "soft" materials like annealed iron, which can be magnetized but do not tend to stay magnetized, and magnetically "hard" materials, which do. Permanent magnets are made from "hard" ferromagnetic materials such as alnico and ferrite that are subjected to special processing in a strong magnetic field during manufacture to align their internal microcrystalline structure, making them very hard to demagnetize. To demagnetize a saturated magnet, a certain magnetic field must be applied, and this threshold depends on coercivity of the respective material. "Hard" materials have high coercivity, whereas "soft" materials have low coercivity. The overall strength of a magnet is measured by its magnetic moment or, alternatively, the total magnetic flux it produces. The local strength of magnetism in a material is measured by its magnetization.
An electromagnet is made from a coil of wire that acts as a magnet when an electric current passes through it but stops being a magnet when the current stops. Often, the coil is wrapped around a core of "soft" ferromagnetic material such as mild steel, which greatly enhances the magnetic field produced by the coil.

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  1. Astronuc

    Tetrataenite - L1[sub]0[/sub]-type FeNi

    Tetrataenite is one of the mineral phases found in meteoric iron. Various groups are attempting to synthesize on a commercial scale to replace REE-based magnets. https://en.wikipedia.org/wiki/Tetrataenite...
  2. T

    Computational project ideas for magnetic materials?

    For my end-of-semester project, I was tasked to investigate an aspect of magnetism/magnetic materials, to do some literature review on the topic, and code a mathematical model and display my results graphically. I couldn't find anything I wanted to do, so I asked the professor to assign me a...
  3. D

    A B.D. Cullity § C.D. Graham-Introduction Magnetic Materials Solutions

    Hi, I have to check some questions answers for my homework (Problem 3.5 and 3.6). Please help me find this book solution manual.
  4. S

    Exploring Magnetic Materials for 9th Graders: Zinc vs. Stainless Steel Fasteners

    I am putting together a hands on activity for ninth graders, which will include testing different materials to determine whether they are attracted to a magnet. I have collected fasteners (screws, nails, bolts), and surprised that the fasteners I purchased labeled "zinc" are attracted to the...
  5. A

    Two Coaxial Linear Magnetic Materials

    Homework Statement Consider a two-layered cylindrical wire with inner-layer permeability μ1 and outer-layer permeability μ2. A line current I runs through the center in the z direction. Calculate the bound currents and the magnetic field produced by the bound currents. Homework Equations [1]...
  6. KronosZ

    Conservation of Energy and current

    Assume there is a table with an infinite long wire passing through the centre and few iron pieces lying around the wire on the table. Now I pass current through the wire which creates electro magnetic field due to which all the iron particles get magnetic potential energy. They are attracted...
  7. S

    Capacitor with magnetic dielectric

    Odd question, would anybody know what would happen if a parallel plate capacitor (good conductor) had a soft magnetic material (fairly poor conductor) as a dielectric? What would be the DC/AC electrical characteristics of this?
  8. J

    Magnet with Non Magnetic Materials

    Dear Friends Could anyone tell me whether we can stich (or) Join Magnets with Non Magnetic Materials? Is there any Possibilities? Thanks for Your Replies in Advance
  9. P

    Field due to Magnetic Materials

    Say you have a paramagnetic (or diamagnetic) sphere (or some other shape) and you apply a field of H = 10 Oe. Now, we have H=(1/\mu)B-M. That would indicate that outside of the material, B and H are essentially the same, right? B = 10 Gauss, outside of the material. But shouldn't the...
  10. S

    Effect of magnetic materials on field created by current

    Hello, Imagine I have an infinite wire with a DC current. Around it there two rings of ferro-magnetic material, not far from each other. Does changing the mu_r of one of the first ring, changes the magnetic field in the second ring? - If I consider just Ampére law (macroscopic...
  11. S

    Will a magnetic field pass through non magnetic materials

    Hi and thanks for helping me with these physics questions. Firstly, will a magnetic field pass through non magnetic materials as though it was air? For example, will a magnet still attract another magnet when copper or wood is placed in between it? I understand that if the material in...
  12. M

    Strongest Magnetic Materials: Rare Earths and NdBFe

    As far as I am aware, Rare Earths and particularly NdBFe is the strongest known magnetic material. Is this true and what is the strongest magnetic material known that it is in common use and what is possible theoretically? Thank you.
  13. N

    Are superconductors dia magnetic materials?

    are superconductors dia magnetic materials?? if so, what are similarities between them??
  14. C

    Magnetic Materials: Why are Some Magnetic?

    Homework Statement today, my teacher asked us a question. he asked, have you ever wondered why materials are magnetic? why are some materials magnetic and some are not? are the magnetic materials specifically chosen to be magnetic or non magnetic? what makes them magnetic? and my class...
  15. N

    Permanent effects on electron spin by magnetic materials?

    Hello all, I feel somewhat strange posting on this forum because I'm majoring in biology and we're supposed to be the enemies of physics, but I've come across a question that I can't seem to find an answer to; this is actually in regards to independent research. Does instantaneous or prolonged...
  16. P

    Magnetic Materials: Exploring the Mystery of Steel Core Magnetization

    When the current in solenoid is turned off a steel core stays magnetized. The tiny atomic magnets remain lined up, even when the external field is removed. Why is that so?