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Solid state part 15
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Magnetic properties of solids

Shaillee Kaushal is teaching live on Unacademy Plus

Shaillee Kaushal
Faculty in Chemistry with a teaching experience of 14 years. Specialised in teaching for boards and competitions.

Unacademy user
Thanks you sir is very inspiring....!
plz mam inorganic aur organic complete karwa dijiye
mam when will you finish the full portions?? it's an awesome course, it's helping me a lot, please reply me mam
soon my dear
Sudharshan R
a year ago
thank you very much mam
  1. XII-01 Solid State - part 15

  2. MAGNETIC PROPERTIES . Paramagnetic solids - Diamagnetic Solids - Ferromagnetic Solids

  3. PARAMAGNETIC SOLIDS Occurs due to one or more unpaired electrons in an atom > Such solids are weekly attracted by the magnetic field >They become parallel to the field when placed in magentc field Resultant magnetic field for n-unpaired electrons may be calculated as: Hm n(n2)

  4. They are weakly repelled by magnetic field. All electrons have paired spins. Example NaCl, TiO2,Zr02, KCl etc. TiO2 shows paramagnitism due to non stochiometry

  5. These are strongly attracted by external magentic field >They do not loose their magnetism even if external magnetic field is removed Only three elements, iron (Fe), cobalt (Co) and nickel (Ni) show ferromagnetism at room temperature some other example are FeO, Cr02 (used in making magnetic tapes for use in cassette recorders Ferromagneti sm arise due to spontaneous allignment of magnetic moments due to unpaired electrons TITtt A small volume of solid where the unpaired electrons allign each other are called domains

  6. Antiferromagnetic solids Ferromagnetic solids Ferrimagnetic solids

  7. ANTIFERROMAGNETIC SOLIDS In this the domains are aligned in parallel and antiparallel directions in equal numbers. As a result the magnetic moment is zero Example:-MnO, MnO2, Mn203 etc.

  8. In this the domains are arranged in parallel and antiparallel directions in unequal numbers. Therfore they have a net magnetic moment Examples: Fe,04, and ferrites with the formula M2*Fe204(M Zn, Cn, Mg, etc) lie

  9. Influence of temperature on magnetic character of solids: All magnetically ordered solids (ferromagnetic, antiferromagnetic and ferrimagnetic) change into paramagnetic state on increase in temperature. This is due to randomisation of their spin. (i) Ferromagnetic solid, Fe,04 becomes paramagnetic when heated to 850K (i) Antiferromagnetic solid V203 becomes paramagnetic when heated to 750 K. This temperature at which ferromagnetic changes to paramagnetic in called cuie point or cie temperatuue