scholarly journals Thermoelectric Power Due to Small Polaron Hopping Motion in Disordered Systems

1985 ◽  
Vol 132 (2) ◽  
pp. 641-652 ◽  
Author(s):  
G. P. Triberis
Keyword(s):  
Thermoelectric Power ◽  
Disordered Systems ◽  
Small Polaron ◽  
Polaron Hopping ◽  
Small Polaron Hopping

Electrical transport properties of single-crystalline Mn–Zn ferrous ferrite

2001 ◽  
Vol 16 (3) ◽  
pp. 774-777 ◽  
Author(s):  
Yong-Chae Chung ◽  
Han-Ill Yoo
Keyword(s):  
Transport Properties ◽  
Thermoelectric Power ◽  
Electrical Transport ◽  
Small Polaron ◽  
Electrical Transport Properties ◽  
Polaron Hopping ◽  
Single Crystalline ◽  
Small Polaron Hopping ◽  
Hopping Model ◽  
Cation Redistribution

Electrical transport properties, electrical conductivity, and thermoelectric power of a single-crystalline Mn0.45Zn0.43Fe2.12O4 were measured as functions of temperature in the range of 25 to 1000 °C. According to the small polaron hopping model, the values of the activation energy for small polaron hopping (EH) were obtained from the conductivity data in three different temperature regions: 0.032 eV for T < TC, 0.12 eV for TC < T < 600 °C, and 0.25 eV for 600 °C < T < 1000 °C. The behavior of conductivity and thermoelectric power data above TC is discussed in connection with cation redistribution.

The effect of the density of states on the conductivity of the small-polaron hopping regime in disordered systems

1991 ◽  
Vol 3 (3) ◽  
pp. 337-346 ◽  
Author(s):  
G P Triberis ◽  
X Zianni ◽  
A N Yannacopoulos ◽  
V C Karavolas
Keyword(s):  
Density Of States ◽  
Disordered Systems ◽  
Small Polaron ◽  
Polaron Hopping ◽  
Small Polaron Hopping

scholarly journals Small Polaron Hopping Conduction in Samples of Ceramic La1 · 4Sr1 · 6Mn2O7 · 06

1999 ◽  
Vol 52 (2) ◽  
pp. 187 ◽  
Author(s):  
H. Nakatsugawa ◽  
E. Iguchi ◽  
W. H. Jung ◽  
F. Munakata
Keyword(s):  
Thermoelectric Power ◽  
Ceramic Sample ◽  
Small Polaron ◽  
Hopping Conduction ◽  
Two Dimensional ◽  
Polaron Hopping ◽  
Small Polaron Hopping ◽  
Spin Ordering ◽  
The One ◽  
Increasing Temperature

The ceramic sample of La1 · 4Sr1 · 6Mn2O7 · 06 exhibits the metal-insulator transition and a negative magnetoresistance in the vicinity of the Curie temperature (T ⋍ 100 K). The dc magnetic susceptibility between 100 K and 280 K is nearly constant and decreases gradually with increasing temperature above 280 K. The measurements of dc resistivity and the thermoelectric power indicate that small polaron hopping conduction takes place at T > 280 K. The spin ordering due to the two-dimensional d x 2 ¡ y 2 state occurring at T > 280 K is directly related to the hopping conduction above 280 K, although the spin ordering due to the one-dimensional d 3z 2 ¡ r 2 state takes place at T > TC. The two-dimensional d x 2 ¡ y 2 state extending within the MnO2 sheets starts to narrow and leads to the carrier localisation at 280 K. The effective number of holes in this sample estimated from the thermoelectric power is considerably smaller than the nominal value. This indicates that the small polaron hopping conduction takes place predominantly within the in-plane MnO2 sheets. A discussion is given of the experimental results of the ceramic sample of La2/3Ca1/3MnO2·98.

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