Some Important Features of Manganites

R. J. Singh

Physics Department, Aligarh Muslim University, Aligarh, India.

DOI: 10.4236/jmp.2013.42027                

Abstract

Manganites are very complex systems because of interplay among charge, spin, orbital and lattice degrees of freedom. To come closer to the understanding of its nature, we discuss its three important features: 1) correlation between magnetization and electrical resistivity in the same temperature range; 2) detection of chemical constitution and the arrangement of Mn³⁺ and Mn⁴⁺ ions at different hole concentrations; and 3) how electrical current flows through double exchange in manganites. The first feature will be discussed for three-dimensional manganies. The features 2 and 3 are inscrutable in three-dimensional manganites. So they will be discussed for one-dimensional manganites and then generalized. One-dimensional solid has been discussed because it may give a see-through picture of various aspects of manganites. All the discussions will be done through a representative example of La_1-xCa_xMnO₃, because it is the intermediate bandwidth manganite; has been most widely investigated and has the highest magnetoresistance. If two things: 1) magnetization and resistivity as a function of temperature at various magnetic fields; and 2) phase diagrams of other manganites are known, their properties can be understood by the discussion of the three features mentioned above.

Keywords

Manganites; Electrical Resistivity; Magnetization; Phase Diagram

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	A. J. Millis, P. B. Littlewood and B. I. Shraiman, “Double Exchange Alone Does Not Explain the Resistivity of LaSrMnO,” Physical Review Letters, Vol. 74, No. 25, 1995, pp. 5144-5147. doi:10.1103/PhysRevLett.74.5144
[2]	A. J. Millis, B. I. Shraiman and R. Mueller, “Dynamic Jahn-Teller Effect and Colossal Magnetoresistance in La1-xSrx MnO3,” Physical Review Letters, Vol. 77, No. 1, 1996, pp. 175-178. doi:10.1103/PhysRevLett.77.175
[3]	S. K. Sarker, “Phase Transition in the Double Exchange Model: A Schwinger Boson Approach,” Journal of Physics: Condensed Matter, Vol. 8, No. 37, 1996, pp. L515- L521.
[4]	E. Dogotto, S. Yunoki, A. L. Maluezzi, A. Morento and H. Ju, “Ferromagnetic Kondo Model for Manganites: Phase Diagram, Charge Segregation and Influence of Quantum Localized Spins,” Physical Review, Vol. 58, No. 10, 1998, pp. 6414-6427.
[5]	E. Dogotto, T. Hotta and A. Moreo, “Colossal Magnetoresistant Materials: The Key Role of Phase Separation,” Physics Reports, Vol. 344, No. 1-3, 2001, pp. 1-153. doi:10.1016/S0370-1573(00)00121-6
[6]	Y. Tokuro, “Critical Features of Magnetoresistive Manganites,” Reports on Progress in Physics, Vol. 69, No. 3, 2006, pp. 797-851. doi:10.1088/0034-4885/69/3/R06
[7]	L. P. Gorkov and V. Z. Kresnin, “Mixed Valence Manganites, Fundamental and Main Properties,” Physics Reports, Vol. 400, No. 3, 2004, pp. 149-208. doi:10.1016/j.physrep.2004.08.003
[8]	M. B. Salamon and M. Jaime, “The Physics of Manganites: Structure and Transport,” Reviews of Modern Physics, Vol. 73, No. 3, 2001, pp. 583-628. doi:10.1103/RevModPhys.73.583
[9]	E. Dogotto, “Open Questions in CMR Manganites, Relevance of Clustered States and Anologies with Other Compounds including the Cuprates,” New Journal of Physics, Vol. 7, 2005, pp. 67-95. doi:10.1088/1367-2630/7/1/067
[10]	C. N. R. Rao and R. Reveau, “Crystal Structure of Ferromagnetic Insulated La1-xCaxMnO3,” World Scientific, Singapore City, 1998.
[11]	T. V. Ramkrishnanm, H. R. Krishnamurthy, S. R. Hasan and G. V. Pai, “The Theory of Insulator Metal Transition and Colossal Magnetoresistance in Doped Manganites,” Physical Review Letters, Vol. 92, No. 15, 2004, Article ID: 157203. doi:10.1103/PhysRevLett.92.157203
[12]	H. R. Krishnamurthy, “A New Theory of Doped Manganites Exhibiting Colossal Magnetoresistance,” Pramana: Journal of Physics, Vol. 64, No. 6, 2005, pp. 1063-1074. doi:10.1007/BF02704168
[13]	W. E. Picket and D. J. Singh, “Comment on: Density Functional Distribution of the Electronic Structure of LaMnO3 (M= Sc, Ti, V, Cr, Mn, Fe, Co, Ni),” Physical Review, Vol. B53, 1996, pp. 1146-1160.
[14]	G. Li, H.-D. Zhou, S. J. Feng, X.-J. Fan, X.-G. Li and Z. D. Wang, “Competition between Ferromagnetic Metallicand Paramagnetic Insulating Phases in Manganites,” Journal of Applied Physics, Vol. 92, No. 3, 2002, pp. 1406-1410. doi:10.1063/1.1490153
[15]	S. Khan and R. J. Singh, “Temperature Profile of Resistivity of Manganites,” Modern Physics Letters B, Vol. 21, No. 26, 2007, pp. 1795-1805. doi:10.1142/S0217984 907014127
[16]	P. Schiffer, A. P. Ramirez, W. Bao and S.-W. Cheong, “Low Temperature Magnetoresistance and Magnetic Phase,” Physical Review Letters, Vol. 75, No. 18, 1995, pp. 3336-3339. doi:10.1103/PhysRevLett.75.3336
[17]	D. Q. Liao, Y. Sun, R. F. Yang, Q. A. Li and Z. H. Cheng, “Spontaneous Magnetization and Resistivity Steps in the Bilayered Manganite (La0.5Nd0.5)1.2Sr1.8Mn2O7,” Physical Review B, Vol. 74, 2006, Article ID: 174434.
[18]	C. Zener, “Interaction between the D-Shells in the Transition Metals. II. Ferromagnetic Compounds of Manganese with Perovskite Structure,” Physical Review, Vol. 82, No. 3, 1951, pp. 403-405. doi:10.1103/PhysRev.82.403
[19]	M. H. Tsai, Y. H. Tang, H. Chou and W. I. Wu.
[20]	P. W. Anderson, “Antiferromagnetism. Theory of Super-Exchange Interaction,” Physical Review, Vol. 79, No. 2, 1950, pp. 350-356. doi:10.1103/PhysRev.79.350
[21]	J. B. Goodenough, “Theory of the Role of Covalence in the Perovskite Type Manganites [La, M(II)] MnO3,” Physical Review, Vol. 100, No. 2, 1955, pp. 564-573. doi:10.1103/PhysRev.100.564
[22]	J. B. Goodenough, “An Interpretation of the Magnetic Properties of the Perovskite Type Mixed Crystals La1?xSrxCoO3?λ,” Journal of Physics and Chemistry of Solids, Vol. 6, No. 2-3, 1958, pp. 287-297. doi:10.1016/0022-3697(58)90107-0
[23]	J. Kanamori, “Superexchange Interaction and Symmetry Properties of Electron Orbitals,” Journal of Physics and Chemistry of Solids, Vol. 10, No. 2-3, 1959, pp. 87-98. doi:10.1016/0022-3697(59)90061-7
[24]	P. Raychaudhuri, K. Sheshadri, P. Taneja and S. Bandophadhyay, “Spin Polarized Tunnelling in the Half Metallic Ferromagnets La0.7?xHoxSr0.3MnO3 (x = 0 and 0.15): Experiment and Theory,” Physical Review B, Vol. 59, 1999, pp. 13919-13926.
[25]	A. de Andres, M.-G. Hernandez and J. I. Martinetz, “Conduction Channels and Magnetoresistance in Polycrystalline Manganites,” Physical Review B, Vol. 60, 1999, pp. 7328-7334.
[26]	J. M. Luttinger, “An Exactly Soluble Model of a Many Fermion System,” Journal of Mathematical Physics, Vol. 4, No. 9, 1963, pp. 1154-1162. doi:10.1063/1.1704046