Abstract
Pressure dependences of the thermopower and electrical resistivity of the La0.75Ca0.25MnO3 manganite are measured in the pressure range 0–20 GPa at room temperature. The absolute value of the thermopower increases in the pressure range 0–3 GPa and decreases at higher pressures. At the same time, the electrical resistivity decreases over the entire pressure range. It is found that the competing effect of the closing of the bandgap, which is determined by the activation energy for the thermopower, and the pressure broadening of the d bands is the cause of the observed behavior of the thermoelectric properties of La0.75Ca0.25MnO3, which is untypical for the majority of dielectrics and semiconductors with single-band unipolar conductivity in the absence of phase transitions and is accompanied by a change in the sign of the pressure coefficient of the thermopower. The interrelation between the magnetic and thermoelectric properties of manganites under pressure is analyzed in the framework of the double exchange model. The causes of the considerable decrease in the pressure coefficients of the insulator-metal transition and Curie temperatures under pressure experimentally observed in manganites are discussed.
Similar content being viewed by others
References
E. Dagotto, T. Hotta, and A. Moreo, Phys. Rep. 344, 1 (2001).
C. Zener, Phys. Rev. 82, 403 (1951).
P. W. Anderson and H. Hasegawa, Phys. Rev. 100, 675 (1955).
P.-G. De Gennes, Phys. Rev. 118, 141 (1960).
P. Postorino, A. Congeduti, P. Dore, et al., Phys. Rev. Lett. 91, 175501 (2003).
A. Congeduti, P. Postorino, E. Caramagno, et al., Phys. Rev. Lett. 86, 1251 (2001).
C. Meneghini, D. Levy, S. Mobilio, et al., Phys. Rev. B 65, 012111 (2001).
D. P. Kozlenko, S. E. Kichanov, V. I. Voronin, et al., Pis’ma Zh. Éksp. Teor. Fiz. 82, 501 (2005) [JETP Lett. 82, 447 (2005)].
M. F. Hundley and J. J. Neumeier, Phys. Rev. B 55, 11511 (1997).
H. Y. Hwang, T. T. M. Palstra, S.-W. Cheong, and B. Batlogg, Phys. Rev. B 52, 15 046 (1995).
I. M. Tsidil’kovskiĭ, V. V. Shchennikov, and N. G. Gluzman, Fiz. Tekh. Poluprovodn. (Leningrad) 17, 958 (1983) [Sov. Phys. Semicond. 17, 604 (1983)].
S. V. Ovsyannikov and V. V. Shchennikov, Pis’ma Zh. Éksp. Teor. Fiz. 80, 41 (2004) [JETP Lett. 80, 35 (2004)].
S. V. Ovsyannikov, V. V. Shchennikov, and A. Misyuk, Pis’ma Zh. Éksp. Teor. Fiz. 80, 459 (2004) [JETP Lett. 80, 405 (2004)].
V. V. Shchennikov, S. V. Ovsyannikov, A. Y. Derevskov, and V. V. Shchennikov, Jr., J. Phys. Chem. Solids 67, 2203 (2006).
L. G. Khvostantsev, L. F. Vereshchagin, and N. M. Uliyanitskaya, High Temp. High. Press. 5, 261 (1973).
D. A. Polvani, J. F. Meng, M. Hasegawa, et al., Rev. Sci. Instrum. 70, 3586 (1999).
R. D. Barnard, Thermoelectricity in Metals and Alloys (Taylor and Francis, London, 1972).
T. T. M. Palstra, A. P. Ramirez, S.-W. Cheong, et al., Phys. Rev. B 56, 5104 (1997).
R. Mahendrian, S. K. Tiwary, A. K. Raychaudhuri, et al., Phys. Rev. B 53, 3348 (1996).
N. F. Mott and E. A. Davis, Electronic Processes in Non-Crystalline Materials, 2nd ed. (Clarendon, Oxford, 1979; Mir, Moscow, 1982).
S. I. Vecherskiĭ, N. N. Batalov, N. O. Esina, and G. Sh. Shekhtman, Fiz. Tverd. Tela (St. Petersburg) 45, 1569 (2003) [Phys. Solid State 45, 1648 (2003)].
A. S. Panfilov and I. V. Svechkarev, Fiz. Tekh. Vys. Davleniĭ, No. 2, 59 (1980).
V. Heine, Phys. Rev. 153, 673 (1967).
N. Furukawa, in Physics of Manganites, Ed. by T. A. Kaplan and S. D. Mahanti (Kluwer Academic/Plenum, New York, 1999), pp. 1–38.
W. A. Harrison, The Electronic Structure and Properties of Solids (Freeman, San Francisco, 1980).
V. Laukhin, J. Fontcuberta, J. L. Garcia-Munoz, and X. Obradors, Phys. Rev. B 56, R10 009 (1997).
J. Fontcuberta, V. Laukhin, and X. Obradors, Phys. Rev. B 60, 6266 (1999).
D. P. Kozlenko and B. N. Savenko, J. Phys.: Condens. Matter 16, 9031 (2004).
G. Zhao, K. Conder, H. Keller, and K. A. Muller, Nature 381, 676 (1996).
Author information
Authors and Affiliations
Additional information
Original Russian Text © D.P. Kozlenko, S.V. Ovsyannikov, V.V. Shchennikov, V.I. Voronin, B.N. Savenko, 2007, published in Pis’ma v Zhurnal Éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 85, No. 4, pp. 242–246.
Rights and permissions
About this article
Cite this article
Kozlenko, D.P., Ovsyannikov, S.V., Shchennikov, V.V. et al. Thermoelectric properties of La0.75Ca0.25MnO3 manganite at ultrahigh pressures up to 20 GPa. Jetp Lett. 85, 203–207 (2007). https://doi.org/10.1134/S0021364007040042
Received:
Issue Date:
DOI: https://doi.org/10.1134/S0021364007040042