MAGNETISM ELECTRON TRANSPORT MAGNETORESISTIVE LANTHANUM CALCIUM MANGANITE

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3.1.2.3 Contacts 26
3.1.2.4 Reproducibility 27
3.1.2.5 Apparatus 28
3.1.3 Analysis 29
3.1.3.1 Metals 30
3.1.3.1.1 Impurity scattering 30
3.1.3.1.2 Electron-electron scattering 31
3.1.3.1.3 Electron-phonon scattering 31
3.1.3.2 insulators/semiconductors 31
3.1.3.2.1 Band insulators/semiconductors 32
3.1.3.2.2 Polarons 33
3.1.3.2.3 Diffusive Conductivity 35
3.1.3.2.4 Variable range Hopping 35
3.1.3.3 Poor Metals / Heavily doped semiconductors 37
3.1.3.4 Phase transitions 38
3.2 Magnetism 3 9
3.2.1 Measurement 39
3.2.1.1 Apparatus 39
3.2.2 Analysis 43
3.2.2.1 Diamagnetism and Paramagnetism 44
3.2.2.1.1 Larmor diamagnetism 44
3.2.2.1.2 Conduction electron diamagnetism 46
3.2.2.1.3 Pauli paramagnetism 46
3.2.2.1.4 Curie paramagnetism 47
3.2.2.2 Ferromagnetism 49
3.2.2.2.1 Weiss molecular field model 50
3.2.2.2.2 Itinerant electron Model 53
3.2.2.2.3 Generalized Model 55
3.2.2.2.4 Critical region 59
3.2.2.2.5 Landau mean field theory 60
3.2.2.2.6 Arrott Plot 61
3.2.2.2.7 The Curie temperature 61
3.2.2.2.8 Spin waves 63
3.2.2.2.9 Irreversibility 66
3.2.2.3 Antiferromagnetism 69
3.2.2.4 Ferrimagnetism 71
3.2.2.4.1 Mean field model for Gd0.67Ca0.33MnO3 72
3.3 Heat Capacity 7 6
3.3.1 Measurement 77
3.3.1.1 Apparatus 78
3.3.2 Analysis 78
3.3.2.1 Electronic specific heat 78
3.3.2.2 Phonon specific heat 79
4. INTRINSIC ELECTRICAL TRANSPORT AND MAGNETIC
PROPERTIES OF LA 0.67 CA 0.33 MNO 3 AND LA 0.67 SR 0.33 MNO 3 MOCVD
THIN FILMS AND BULK MATERIAL 8 0
4.1 Magnetism 8 1
4.1.1 Low Temperature Excitations 83