Magnetic Perovskites (eBook)

Asish K. Kundu (Ph.D., JNCASR, Bangalore) is at present Associate Professor of Physics & Ex-Head of Natural Sciences Discipline at the IIITDM, Jabalpur. He is a Visiting Research Faculty and CNRS research fellow at CRISMAT Laboratory, France. Also, he was a visiting researcher at Angstrom Laboratory, Sweden and a DRDO scientist at Solid State Physics Laboratory, Delhi. He is a recipient of UGC-CSIR Junior Research Fellowship in the year 2001 and also awarded BOYSCAST Fellowship for the year 2011 by DST Government of India.  His research in perovskites includes magnetic materials, magnetoresistance materials and multiferroicity of transition metal oxides. He has published more than 40 papers and two books in these areas.

Preface 7
Contents 8
About the Author 10
1 Introduction to Magnetic Perovskites 11
1.1 Importance of Perovskites 11
1.2 Description of Perovskite Structure 13
1.3 Syntheses of Few Perovskites 15
1.3.1 Single-Crystalline Perovskite Cobaltites 16
1.3.1.1 Floating Zone Melting Technique 16
1.4 Significant Properties of Perovskites 18
1.4.1 Magnetic and Electronic Properties 20
1.4.1.1 Magnetic Properties 20
1.4.1.2 Zener Double-Exchange (DE) 21
1.4.1.3 Superexchange Interaction 23
1.4.1.4 Electrical Properties 24
1.4.2 Colossal Magnetoresistance (CMR) 25
1.4.3 Effect of Cation Size and Disorder on Properties 28
1.4.4 Electronic Phase Separation in Perovskites 30
1.4.5 Spin Glass Behavior in Perovskites 35
1.4.6 Multiferroicity in Perovskites 38
References 41
2 Electronic Phase Separation and Glassy Behavior in Magnetic Perovskites 46
2.1 Introduction 46
2.2 Manganese-Centered Magnetic Perovskites 47
2.2.1 Electronic Phase Separation (EPS) in (La12212xLnx)0.7Ca0.3MnO3 (Ln = Pr, Nd, Gd, and Y) 49
2.2.2 Electronic Phase Separation (EPS) in (La12212xLnx)0.7(Ba/Sr)0.3MnO3 (Ln = Pr, Nd, Gd, and Dy) 52
2.2.3 Electronic Phase Separation (EPS) in Nd0.5Ca0.52212xSrxMnO3 (X = 0--0.5) 58
2.2.4 Electronic Phase Separation (EPS) in Pr12212xCaxMnO3 (X = 0.3--0.4) 61
2.2.5 Glassy Ferromagnetism in Ln0.7Ba0.3MnO3 (Ln = La, Nd, and Gd) 62
2.3 Cobalt-Centered Magnetic Perovskites 66
2.3.1 Electronic Phase Separation in La0.72212xLnxCa0.3CoO3 (Ln = Pr, Nd, Gd, and Dy) 67
2.3.2 Spin Glass Behavior in Ln0.7Ca0.3CoO3 (Ln = La, Pr, and Nd) 72
2.3.3 Spin Glass Behavior in La12212xSrxCoO3 76
References 79
3 Ordered-Disordered Perovskite Cobaltites 82
3.1 Introduction 82
3.2 Crystal Structure of Perovskite Cobaltites 84
3.3 Magnetic and Electron Transport Properties 90
3.3.1 Disordered Perovskite Cobaltites 92
3.3.2 Ordered Perovskite Cobaltites: A Special Case for Comparison with La--Ba--Co Disordered Phase 101
References 110
4 Bismuth-Centered Perovskite Multiferroics 113
4.1 Introduction 113
4.2 Bismuth-Centered Magnetic Perovskites 116
4.2.1 Magnetic and Electrical Properties of La0.5Bi0.5MnO3 116
4.3 Magnetic Perovskites La0.5Bi0.5MnO3 Doped with Cobalt and Nickel 118
4.3.1 Magnetotransport Properties of Single-Phase Bulk La0.5Bi0.5Mn12212xMxO3 (M = Co, Ni) 119
4.3.2 Dielectric Properties of La0.5Bi0.5Mn0.67Co0.33O3 123
4.3.2.1 Bulk Phase of La0.5Bi0.5Mn0.67Co0.33O3 123
4.3.2.2 Thin Films of La0.5Bi0.5Mn0.67Co0.33O3 125
4.4 Other Bismuth-Centered Magnetic Perovskites 129
4.4.1 Magnetotransport Properties of Bulk La0.6Bi0.4Mn12212x(Co/Fe/Ni)xO3 129
4.4.2 Magnetodielectric Properties of Bulk La0.6Bi0.4Mn0.6Co0.4O3 135
4.4.3 Magnetotransport-Dielectric Properties of Bulk La12212xBixMn12212yFeyO3 Series 138
4.4.3.1 Single-Phase Bulk La0.5Bi0.5Mn0.5Fe0.5O3 138
4.4.3.2 Single-Phase Bulk La0.5Bi0.5Mn0.7Fe0.3O3, La0.5Bi0.5Mn0.3Fe0.7O3 and La0.3Bi0.7Mn0.3Fe0.7O3 143
4.4.3.3 Single-Phase Bulk La0.8Bi0.2Mn12212yFeyO3 150
4.4.4 Magnetotransport Properties of Bulk (La/Sr/Bi)(MnFe/Cr)O3 Perovskites 157
4.5 Bismuth-Centered Ordered Magnetic Perovskites La22212xBixMn(Co/Ni)O6 157
4.5.1 Magnetic Properties 158
4.5.2 Electrical Properties 161
References 164
Index 168