Abstract
The measurements of electrical conductivity (σ) in the temperature range 450 to 1250 K and thermoelectric power (S) in the temperature range 600 to 1200 K of sintered pressed pellets of rare-earth iron garnets (REIG) with a general chemical formula RE3Fe5O12 (where RE=Y, Gd, Dy, Ho, Er and Yb) are reported. Values corresponding to the crystalline state have been evaluated employing pore fraction correction. It is observed that plots of log σT againstT −1 are linear with breaks in the slopes of temperatureT 1 (lying between 560 and 578 K) andT 2 (~ 1000 K). However, plots ofS againstT −1 are linear over the entire temperature range. The results have been discussed using the usual electrical transport theories and it has been concluded that electrical conduction in these solids up to a temperature of 1250 K is extrinsic in which holes localized on Fe3+ sites (Fe4+ centres created by native defects) conduct via a thermally activated hopping mechanism. Mobility activation energy, mobility and the number of such centres in each garnet are also evaluated.
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References
F. Bertaut andF. Forrat,Compt. Rend. Acad. Sci. Paris 242 (1956), 382.
S. Geller andM. A. Gilleo,Acta. Cryst. 10 (1957) 239.
Idem, J. Phys. Chem. Solids 3 (1957) 30.
R. Pauthnet,Compt. Rend. Acad. Sci. Paris 242 (1956) 1859;243 (1956) 1499.
F. Pertaut andR. Pauthnet,Proc. Inst. Elect. Eng. Part B Suppl. 104 (1957) 261.
R. W. Copper, W. A. Crosaley, J. L. Page andR. F. Pearson,J. Appl. Phys. (USA) 39 (1968) 555.
R. S. Tebble andP. J. Craik, “Magnetic Materials” (John Wiley, London, 1969).
K. J. Standley, “Oxide Magnetic Materials” (Clarendon Press, Oxford, 1972).
F. F. Y. Wang,Treat. Mater. Sci. Technol. 2 (1973) 279.
R. Alenard andJ. C. Barbier,J. Phys. Rad. 20 (1959) 378.
S. Geller, H. J. Williams andR. C. Sherwood,Phys. Rev. 123 (1961) 1692.
R. F. Pearson,J. Appl. Phys. (USA) 33 (1962) 1236.
C. D. Brandle andS. Blank,IEEE Trans. Mag. Mag. 12 (1976) 14.
E. E. Anderson,J. Appl. Phys. (USA) Suppl. 30 (1959) 299.
D. Elwell andA. Dixon,Solid State Commun. 6 (1968) 585.
R. E. Fountana andD. J. Epsteen,Mat. Res. Bull. (USA) 6 (1971) 959.
Ya. M. Ksendzov, A. M. Koten Nikova andV. V. Markov,Sov. Phys. Solid State (USA) 15 (1974) 1563.
P. K. Larsen andR. Metselaar,Phys. Rev. B14 (1976) 2520.
V. R. Yadava andH. B. Lal,Jap. J. Appl. Phys. 18 (1979) 2229.
Idem, Canad. J. Phys. 57 (1979) 1204.
V. R. Yadava, PhD thesis, Gorakhpur University, Gorakhpur, India (1980).
H. B. Lal, B. K. Verma andN. Dar,Ind. J. Cryogenic 1 (1976) 119.
H. B. Lal, V. Pratap andA. Kumar,Pramana 9 (1978) 409.
H. B. Lal,J. Phys. C. Solid State Phys. 13 (1980) 3969 and our other references therein.
N. Dar andH. B. Lal,Mat. Res. Bull (USA) 14 (1979) 1263.
B. K. Verma, Ph.D. thesis, Gorakhpur University, Gorakhpur, India (1979).
H. B. Lal,J. Mag. Mag. Mat. (USA) 23 (1981), 41, and our other references therein.
R. N. Pandey, V. Pratap andH. B. Lal,Proc. Nat. Acad. Sci. (India) 48A (I) (1978) 1.
A. K. Tripathi andH. B. Lal,Jap. J. Appl. Phys. 49 (1980) 1896.
H. B. Lal andV. Pratap,J. Mater. Sci. 16 (1981) 377, and our other references given therein.
A. K. Tripathi andH. B. Lal,Mat. Res. Bull. (USA) 15 (1980) 233.
A. K. Tripathi, PhD thesis, Gorakhpur University, Gorakhpur, India (1981).
K. Shahi, H. B. Lal andS. Chandra,Ind. J. Pure Appl. Phys. 13 (1975) 1.
G. G. Roberts, in “Transfer and storage of Energy by Molecules”, Vol. 4 (John Wiley, New York, 1974).
H. W. Russel,J. Amer. Ceram. Soc. 18 (1935) 1.
L. Heyne, “Electrochemistry of Mixed Ionic Electronic Conductors in Solid Electrolytes”, edited by S. Geller (Springer-Verlag, New York, 1977) p. 169.
S. M. Grivin,J. Solid State Chem. 25 (1978) 65.
G. V. Subbarao, B. M. Wanklyn andC. N. R. Rao,J. Phys. Chem. Solids 32 (1971) 340.
P. K. Larsen andR. Metselaar,J. Solid State Chem. 12 (1975) 253.
J. B. Goodenough,J. Appl. Phys. (USA) 37 (1966) 1415.
K. Mizushima, M. Tanaka, A. Asai, S. Iida andJ. B. Goodenough,J. Phys. Chem. Solids 40 (1979) 1129.
R. R. Heikes, “Thermoelectricity: Science and Engineering”, edited by R. R. Heikes and R. W. Ure (Interscience, New York, 1961) p. 45.
J. B. Webb, M. Sayer andA. Man Singh,Canad. J. Phys. 55 (1977) 1725.
G. P. Espinosa,J. Chem. Phys. 37 (1962) 2344.
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Lal, H.B., Verma, B.K. & Ram Yadav, V. Electrical transport in heavy rare-earth iron garnets. J Mater Sci 17, 3317–3326 (1982). https://doi.org/10.1007/BF01203501
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DOI: https://doi.org/10.1007/BF01203501