Abstract
Ca3−x Bi x Mn2O7 with the nominal composition x=0.05, 0.1, 0.2 and 0.3 is synthesized by solid-state reaction. The refined X-ray diffraction pattern of Ca2.807Bi0.193Mn2O7 with the nominal Bi3+ content x=0.2 indicates that about 71 % of the Bi3+ ion enters into the Ca2+ (2a) site and the remaining 29 % is in the Ca2+ (4e) site. The doped Bi3+ ion produces a ferromagnetic component in the antiferromagnetic matrix. Below the transition temperature, at about 110 K, the ferromagnetic and antiferromagnetic interactions coexist. The alignment of the magnetic moment is canted at 5 K. The electric transport shows insulating behavior. Around the magnetic transition, at about 110 K, the resistance sharply drops like a well. A model proposed by Glazman and Matveev (GM model) is applied to the thermal variation of the resistance from 40 K to 138 K. Above this temperature, it is due to thermally activated hopping of small polarons with the activation energy of 50 meV. A negative magnetoresistance, 17 %, is observed with the doping content as low as 0.05. The magnetoresistance is due to the spin-polarized inelastic tunneling through nonmagnetic localized states embedded in an insulating barrier.
Similar content being viewed by others
References
P.L. Gai, E.M. McCarron III, Science 147, 553 (1990)
T. Birol, N.A. Benedek, C.J. Fennie, Phys. Rev. Lett. 108, 029901 (2012)
S.J. Moon, H. Jin, K.W. Kim, W.S. Choi, Y.S. Lee, J. Yu, G. Cao, A. Sumi, H. Funakubo, C. Bernhard, T.W. Noh, Phys. Rev. Lett. 101, 226402 (2008)
Q.F. Zhang, W.Y. Zhang, Z.S. Jiang, Phys. Rev. B 72, 142401 (2005)
W. Zhu, L. Pi, Y. Huang, S. Tan, Y. Zhang, Appl. Phys. Lett. 101, 192407 (2012)
S.N. Ruddlesden, P. Popper, Acta Crystallogr. 11, 541 (1958)
I.D. Fawcett, J.E. Sunstrom, M. Greenblatt, M. Croft, K.V. Ramanujachary, Chem. Mater. 10, 3643 (1998)
I.D. Fawcett, E. Kim, M. Greenblatt, M. Croft, L.A. Bendersky, Phys. Rev. B 62, 6485 (2000)
M.V. Lobanov, S.W. Li, M. Greenblatt, Chem. Mater. 15(6), 1302 (2003)
W.H. Jung, J. Mater. Sci. Lett. 19, 2037 (2000)
A.L. Cornelius, B.E. Light, Phys. Rev. B 68, 014403 (2003)
H. Ohnishi, T. Kosugi, T. Miyake, S. Ishibashi, K. Terakura, Phys. Rev. B 85, 165128 (2012)
L.I. Glazman, K.A. Matveev, Sov. Phys. JETP 67, 1276 (1988)
N.F. Mott, E.A. Davis, Electronic Processes in Non-Crystalline Materials, 2nd edn. (Clarendon, Oxford, 1979), p. 37
Y. Lu, M. Tran, H. Jaffres, P. Seneor, C. Deranlot, F. Petroff, J.-M. George, Phys. Rev. Lett. 102, 176801 (2009)
Z.W. Fan, P. Li, E.Y. Jiang, H.L. Bai, J. Phys. D: Appl. Phys. 46, 065002 (2013)
Acknowledgements
This work is supported by the National Natural Science foundation of China (Grant no. 11264024), the Inner Mongolia Natural Science Foundation (Grant no. 2011BS0101), and the Micro-nano magnetic material research group.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Chang, H., Wu, Q. Magnetic and transport properties of electron-doped Ca3−x Bi x Mn2O7 . Appl. Phys. A 115, 1323–1327 (2014). https://doi.org/10.1007/s00339-013-7991-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00339-013-7991-x