Magnetic Materials Topic

Magnets

Concept 6 demos

Hand holding a clear acrylic sheet with iron filings scattered on its surface, placed on an overhead projector

Electricity vs. Magnetism

Revisits familiar electrostatics demonstrations with magnets to show that electric and magnetic forces are fundamentally different phenomena. Students see that both poles of a magnet attract a charged balloon, that …

Dark magnet tray holding a large horseshoe magnet labeled S and N, small red-blue bar magnets, cylindrical rod magnets, a small red horseshoe magnet, and a bar magnet with red N and black S ends

Magnets

An assortment of magnets for demonstrating attraction/repulsion, the impossibility of magnetic monopoles (broken magnets always produce two dipoles), and compass alignment with Earth's field. Useful as a hands-on introduction to …

Hand holding a dark, rough lodestone specimen with several paper clips clinging to it

Lodestone

Students see that magnetism occurs naturally in certain minerals. A lodestone (naturally magnetized magnetite, Fe₃O₄) picks up paper clips and has identifiable north and south poles, just like manufactured magnets.

Magnetic Domains and Magnetization

Concept 4 demos

Horseshoe-shaped radar magnet mounted on a turntable between two ring stands, with a pickup coil suspended between the pole pieces and a connecting box on the table

Barkhausen Effect

Students hear direct auditory evidence that magnetization is not a smooth process. As a magnet rotates near a ferromagnetic core, discrete domain wall jumps induce voltage pulses in a pickup …

Four-panel sequence: top left shows the permalloy bar label, top right shows wire pieces hanging from the bar tip, bottom left shows pieces clinging to the bar held at an angle, bottom right shows pieces falling as the bar is rotated perpendicular to the field

Permalloy Bar

Students see that a high-permeability material (permalloy) becomes magnetized by Earth's field alone when aligned with it, and loses its magnetization when rotated perpendicular. This demonstrates that magnetization depends on …

Red-wound electromagnet coil with iron core picking up dozens of nails from a plastic bin, connected via red wires through a toggle switch to a 6V Energizer lantern battery

Electromagnet

Current through a solenoid with an iron core creates a strong temporary magnet that picks up 20–30 nails. Opening the switch drops nearly all the nails, demonstrating that the magnetization …

Paramagnetism and Diamagnetism

Concept 5 demos

Bismuth bar suspended from thread, oriented perpendicular to a cylindrical magnet mounted in a wooden V-block, with "Bismuth" label visible

Paramagnetism and Diamagnetism

Demonstrates the opposite magnetic responses of paramagnetic and diamagnetic materials. Suspended tungsten (paramagnetic) aligns parallel to the magnet pole, while bismuth (diamagnetic) aligns perpendicular — showing that all materials respond …

Four views of the apparatus: radar magnet with pole piece (top left), full setup with magnet on lab jacks and optical bench (top right), close-up showing condenser lens (bottom left), and projected shadow of a suspended sample between pole pieces (bottom right)

Diamagnetism and Paramagnetism

Suspended samples in a non-uniform magnetic field demonstrate diamagnetic behavior. Bismuth, one of the strongest common diamagnets, visibly orients perpendicular to the field lines. Students see that all materials respond …

Plastic tray of dark blue dyed water resting on wooden blocks, with a desk lamp reflecting off the water surface — no magnets present yet

Diamagnetism of Water

Strong magnets create visible deformations in a thin layer of dyed water, demonstrating that water is diamagnetic — it is weakly repelled by magnetic fields. Students see that magnetic interactions …

Hysteresis

Concept 1 demo

Square array of small magnetic compass needles on bearing pins in a clear acrylic plate, showing spontaneous domain formation with groups of needles aligned in different directions

Magnet Model

A 2D array of magnetic needles on bearing pins models ferromagnetic domains. Students see how dipoles spontaneously form domains, how domain walls shift under an applied field, and how the …

Temperature and Magnetism

Concept 4 demos

Vertical metal stand on black tripod base with torsion wire hanging from top clamp, permanent magnet and burner assembly on middle clamps, rubber tube connecting to blue propane cylinder at right

Curie Temperature

Demonstrates the Curie temperature phase transition: an iron rod held against a permanent magnet by ferromagnetic attraction is heated until it loses its magnetism and swings away, then cools and …

Magnetic disk heat motor: a permalloy disk mounted horizontally on a pivot next to a horseshoe magnet, with a Bernzomatic propane torch positioned to heat the disk rim

Magnetic Disk Heat Motor

A permalloy disk rotates continuously when heated by a propane torch near a horseshoe magnet. Students observe the Curie temperature transition: heated sections lose ferromagnetism and are no longer attracted, …

Apparatus showing glass dish with watch glass and heat pad on left, stacked hard drive magnets on aluminum plate with blue lead brick on lab jack at right

Dysprosium in Liquid Nitrogen

Demonstrates temperature-dependent magnetic phase transitions. Dysprosium pellets cooled in liquid nitrogen (77 K) become ferromagnetic and stick to a magnet. As they warm, they pass through a helimagnetic phase and …