Solid - State Magnetism

1 Introduction.- 1.1 Basic magnetic properties.- 1.1.1 Ferromagnetic materials.- 1.1.2 Paramagnetism.- 1.1.3 Diamagnetism.- 1.1.4 Antiferromagnetism.- 1.1.5 Ferrimagnetism.- 1.1.6 Helimagnetism.- 1.2 Units in magnetism.- 2 Localized magnetism associated with the ion cores.- 2.1 The origins of the magnetic properties of materials.- 2.2 The magnetic moment of a single free ion.- 2.2.1 Hund's rules.- 2.2.2 Combination of L and S to form J.- 2.2.3 Units of magnetic moment.- 2.3 The magnetic moment of an assembly of atoms, without interactions.- 2.4 Paramagnetic susceptibility of an array of atoms.- 2.5 Comparison with experiment.- 2.5.1 Experimental behaviour of rare earth salts and metals.- 2.5.2 Experimental behaviour of transition series salts.- 2.5.3 Crystal field effects.- 2.5.4 Direct measurement of the g-factor.- 2.6 Ferromagnetism in the local moment model, with interactions.- 2.6.1 Calculation of the spontaneous magnetization.- 2.6.2 Relationship between the molecular field coefficient and the Curie Temperature.- 2.6.3 Susceptibility above the Curie temperature.- 2.6.4 Comparison with experiment.- 3 Magnetism associated with band electrons.- 3.1 Collective electron theory: general solution.- 3.2 Paramagnetism without interactions.- 3.2.1 Comparison with experiment.- 3.3 Paramagnetism with interactions.- 3.3.1 Comparison with experiment.- 3.4 Ferromagnetism in the band model.- 3.4.1 Paramagnetism above the Curie temperature.- 3.5 Magnetic moments of pure metals and alloys.- 3.5.1 The rigid band model.- 3.5.2 Nickel.- 3.5.3 Cobalt.- 3.5.4 Iron.- 3.5.5 Face-centred cubic nickel-copper and cobalt-copper alloys.- 3.5.6 Other alloys of nickel and cobalt.- 3.5.7 Face-centred cubic binary alloys between transition elements.- 4 Techniques of making magnetic measurements.- 4.1 Measurement of magnetization.- 4.1.1 The induction method.- 4.1.2 Vibrating sample magnetometer.- 4.1.3 The force method.- 4.2 Measurement of paramagnetic susceptibility.- 4.2.1 The Gouy method.- 4.2.2 Effect of ferromagnetic impurities on susceptibility measurements.- 4.3 Dipole moment methods - SQUIDS.- 4.3.1 SQUID magnetometry.- 4.3.2 The phase of a pair wave.- 4.3.3 Effect of a magnetic field.- 4.3.4 Circular conductor.- 4.3.5 Quantum interference.- 4.3.6 Quantum interferometer.- 4.4 Derivation of spontaneous magnetization from experimental data.- 4.4.1 Measurement of Curie temperature.- 4.5 The generation of magnetic fields.- 4.5.1 Solenoid magnets with air cores.- 4.5.2 Power consumption and dissipation in a solenoid.- 4.5.3 Mechanical effects in solenoids.- 4.5.4 Superconducting solenoids.- 4.5.5 Iron-cored electromagnets.- 4.5.6 Pulsed magnetic fields.- 4.6 The measurement of magnetic field.- 4.6.1 Measurement of magnetic flux.- 4.6.2 Ballistic galvanometer.- 4.6.3 Fluxmeter.- 4.6.4 Electronic integrator.- 4.6.5 Nuclear magnetic resonance.- 4.6.6 The Hall effect.- 4.6.7 Magnetoresistance.- 4.6.8 The measurement of pulsed fields.- 4.6.9 Magnetic potentiometer.- 4.6.10 Measurement of induction.- 5 Magnetic scattering of neutrons and magnetic excitations.- 5.1 Properties of the neutron.- 5.2 Sources of neutrons.- 5.3 Powder diffraction.- 5.3.1 Neutron detectors.- 5.3.2 Single detectors.- 5.3.3 Photographic detection of neutrons.- 5.3.4 Multidetectors.- 5.3.5 Monochromators.- 5.4 Inelastic neutron scattering.- 5.4.1 Results of magnon dispersion experiments with neutrons.- 5.5 The polarization of neutron beams.- 5.5.1 By selective Bragg reflection.- 5.5.2 By using supermirrors.- 5.5.3 By using polarizing transmission filters.- 5.6 Engineering applications of neutron scattering.- 5.7 Magnetic excitations and spin waves.- 5.8 Brillouin zones in metals.- 5.8.1 Interaction between conduction electrons and the lattice periodicity.- 5.9 Spin wave resonance.- 6 Antiferromagnetism, ferrimagnetism and non-collinear magnetic order.- 6.1 Antiferromagnetism.- 6.1.1 Magnetization of the sublattices.- 6.1.2 Susceptibility above the Neel temperature.- 6.1.3 Susceptibility below the Neel temperature.- 6.1.4 Perpendicular susceptibility.- 6.1.5 Parallel susceptibility.- 6.1.6 Effect of crystal anisotropy.- 6.1.7 Antiferromagnetism in metals.- 6.2 Ferrimagnetism.- 6.2.1 Structure of the spinel ferrites.- 6.2.2 Two-sublattice theory of ferrimagnetism.- 6.2.3 Susceptibility of the paramagnetic state above the Curie temperature.- 6.2.4 Magnetization below the Curie temperature.- 6.2.5 Saturation magnetic moment of spinel ferrites.- 6.2.6 Hexagonal ferrites.- 6.2.7 Ferrimagnetic garnets.- 6.2.8 Applications of ferrimagnetic oxides.- 6.2.9 Mechanism of magnetic coupling in ferrimagnetic oxides.- 6.3 Helimagnetism.- 6.3.1 Other non-collinear structures.- 6.3.2 Unusual magnetic materials.- 6.4 The rare earth metals.- 6.4.1 Crystal structures.- 6.4.2 Magnetism in rare earths.- 6.4.3 Magnetic structures of the heavier rare earth metals.- 6.4.4 Magnetic structures of the lighter rare earth metals.- 6.5 Spin glasses.- 6.6 Magnetic amorphous alloys.- 6.6.1 Production of metallic glasses.- 6.6.2 Magnetism in amorphous alloys.- 6.7 High-TC superconducting ceramics.- 7 Exchange interactions in magnetism and hyperfine fields.- 7.1 Exchange interactions in magnetism.- 7.1.1 Heisenberg direct exchange between moments localized on atoms.- 7.1.2 Exchange effects between collective electrons.- 7.1.3 Superexchange.- 7.1.4 Indirect exchange by polarization of the conduction electrons.- 7.1.5 Experimental confirmation of the RKKY model.- 7.1.6 Magnetic interactions which differ between different atomic neighbours.- 7.2 Hyperfine interactions in magnetic materials.- 7.2.1 The Mossbauer effect.- 7.2.2 Nuclear magnetic resonance.- 7.2.3 Nuclear contribution to the specific heat capacity.- 8 Domain magnetism.- 8.1 Basic principles.- 8.1.1 Magnetocrystalline anisotropy.- 8.1.2 Magnetostatic energy.- 8.1.3 Domain boundary walls (Bloch walls).- 8.2 Arrangements of domains.- 8.2.1 Experimental observation of magnetic domains.- 8.2.2 Magneto-elastic energy and magnetostriction.- 8.2.3 Magnetization curves and domain wall equilibrium.- 8.3 Single domain particles.- 8.3.1 Superparamagnetism.- 8.4 Soft magnetic materials.- 8.5 Hard magnetic materials.- 8.5.1 Energy product as a figure of merit.- 8.5.2 Neodymium-iron-boron permanent magnets.- 8.6 Thin magnetic films and whiskers.- 8.7 Magnetic bubbles.- 9 Applications of magnetism.- 9.1 Permanent magnets.- 9.1.1 Energy associated with a magnetic field.- 9.1.2 Energy of a permanent magnet.- 9.2 Applications of soft magnetic materials.- 9.3 Magnetic tape recording.- 9.4 Applications of magnetic bubbles.- 9.5 Imaging by nuclear magnetic resonance.- 9.6 Magnetic phase analysis of alloys.- 9.6.1 Ferromagnetic materials.- 9.6.2 Paramagnetic materials.