Question

Look up the following materials and say which class of magnetic response you would expect each to be.

a. chromium   b. Magnetite c. cobalt d. oxygen e. nitrogen   f. iron oxide   g. platinum    h. Alnico   i. SmCo₅

Answer 1

a)Chromium is remarkable for its magnetic properties: it is the only elemental solid which shows antiferromagnetic ordering at room temperature (and below). Above 38 °C, it transforms into a paramagnetic state

b)Magnetite s feromagnetic it is a mineral and one of the three common naturally-occurring oxides of iron. Its chemical formula is Fe₃O₄, and it is a member of the spinel group. Magnetite is the most magnetic of all the naturally-occurring minerals on Earth.

c) Cobalt is a ferromagnetic metal , the magnetic moment is 1.6–1.7Bohr magnetons per atom.

d) oxygen is paramagnetic is because the oxygen molecule has two unpaired electrons. Electrons not only go around the atom in their orbitals, they also spin, which creates a magnetic field. Unpaired electrons spin in the same direction as each other, which increases the magnetic field effect.

e) nitrogen is diamagnetic due to some unpaired electron

f) iron oxide is antiferromagnetic below ~260 K (Morin transitiontemperature), and exhibits weak ferromagnetism between 260 K.iron oxide Due to its 4 unpaired electrons in 3d shell and have 5 unpaired electrons in 3d shell.

g)Platinum is paramagnetic, whereas nickel and iron are both ferromagnetic

h) Alnico alloys are ferromagnetic it make strong permanent magnets, and can be magnetised to produce strong magnetic fields.

i) samarium–cobalt (SmCo) is feromagnetic magnet, a type of rare earth magnet, is a strong permanent magnet made of an alloy of samarium and cobalt.