Explain the following with suitabale examples :
(i) Ferromagnetism
(ii) Paramagnetism
(iii) Ferrimagnetism
(iv) Antiferromagnetism
(v) 12-16 and 13-15 group compounds.
Explain the following with suitabale examples :
(i) Ferromagnetism
(ii) Paramagnetism
(iii) Ferrimagnetism
(iv) Antiferromagnetism
(v) 12-16 and 13-15 group compounds.
(i) Ferromagnetism The substance like iron, cobalt, nickel, gadolinium, CrO2 etc are strongly attracted by magnetic field. Such substances are called ferromagnetic substances, In solid state, the metal ions are grouped into small regions (domains), which act as small magnet. When such substance is placed in a magnetic field, all the domains get oriented in the direction of the magnetic field and a strong magnetic effect is produced. If the magnetic field is removed the magnetic property persists, Thus, a permanent magnet is formed. This property is called ferromagnetism.
(ii) Paramagnetism Some substances are weakly attracted by a magnetic field. Atoms of these substances have one or more unpaired electrons. Which are attracted by magnetic field. When the external magnetic field is removed, the magnetism is also lost. Thus, the paramagnetism is temporary. Examples of paramagnetic substance are O2,Cu2+,Fe3+,Cr3+ etc.
(iii) Ferrimagnetism In ferrimagnetic substances, the net magnetic moment is small due to unequal number of magnetic moment of domains aligned in paralleland antiparallel directions. These substances lose the ferrimagnetism on heating and become paramagnetic. Examples : Fe3O4,MgFe2O4,ZnFe2O4 etc.
(iv) Antiferromagnetism These substances have domain structure similar to those of ferromagnetic substances but their domains are oppositely oriented and cancel out each other's magnetic moment. MnO is an antiferromagnetic substance.
(v) 12-16 and 13-15 group compounds A large variety of solid state materials have been prepared by combination of group 13 and 15 or 12 and 16 to stimulate average valence of four as in Ge or Si. Typical compounds of groups 13-15 are InSb, AIP and GaAs. Gallium arsenide (GaAs) semiconductors have very fast response and have revolutionised the design of semiconductor devices, ZnS, CdS, CdSe and HgTe are examples of groups 12-16 compounds. In these compounds, bonds are having same ionic character along with covalent. The ionic character depends on the electronegativities of the two elements.
(i) Ferromagnetism The substance like iron, cobalt, nickel, gadolinium, CrO2 etc are strongly attracted by magnetic field. Such substances are called ferromagnetic substances, In solid state, the metal ions are grouped into small regions (domains), which act as small magnet. When such substance is placed in a magnetic field, all the domains get oriented in the direction of the magnetic field and a strong magnetic effect is produced. If the magnetic field is removed the magnetic property persists, Thus, a permanent magnet is formed. This property is called ferromagnetism.
(ii) Paramagnetism Some substances are weakly attracted by a magnetic field. Atoms of these substances have one or more unpaired electrons. Which are attracted by magnetic field. When the external magnetic field is removed, the magnetism is also lost. Thus, the paramagnetism is temporary. Examples of paramagnetic substance are O2,Cu2+,Fe3+,Cr3+ etc.
(iii) Ferrimagnetism In ferrimagnetic substances, the net magnetic moment is small due to unequal number of magnetic moment of domains aligned in paralleland antiparallel directions. These substances lose the ferrimagnetism on heating and become paramagnetic. Examples : Fe3O4,MgFe2O4,ZnFe2O4 etc.
(iv) Antiferromagnetism These substances have domain structure similar to those of ferromagnetic substances but their domains are oppositely oriented and cancel out each other's magnetic moment. MnO is an antiferromagnetic substance.
(v) 12-16 and 13-15 group compounds A large variety of solid state materials have been prepared by combination of group 13 and 15 or 12 and 16 to stimulate average valence of four as in Ge or Si. Typical compounds of groups 13-15 are InSb, AIP and GaAs. Gallium arsenide (GaAs) semiconductors have very fast response and have revolutionised the design of semiconductor devices, ZnS, CdS, CdSe and HgTe are examples of groups 12-16 compounds. In these compounds, bonds are having same ionic character along with covalent. The ionic character depends on the electronegativities of the two elements.
