Application of Variable Range Hopping Model to a Granular Carbon

2011 ◽  
Author(s):  
A. Aparecido-Ferreira ◽  
G. M. Ribeiro ◽  
E. S. Alves ◽  
J. F. Sampaio ◽  
Jisoon Ihm ◽  
...  
Keyword(s):  
Variable Range Hopping ◽  
Variable Range ◽  
Hopping Model ◽  
Variable Range Hopping Model

Variable Range Hopping Resistivity in La2-xSrxCuO4 Nanoparticles Evaluated by Four Point Probe Method

2020 ◽  
Vol 860 ◽  
pp. 142-147
Author(s):  
Suci Winarsih ◽  
Faisal Budiman ◽  
Hirofumi Tanaka ◽  
Tadashi Adachi ◽  
Takayuki Goto ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Thermal Activation ◽  
Resistivity Measurement ◽  
Probe Method ◽  
Charge Carriers ◽  
High Resistivity ◽  
Variable Range Hopping ◽  
Variable Range ◽  
Hopping Model ◽  
Variable Range Hopping Model

We report the results of the resistivity measurement on La2-xSrxCuO4 nanoparticles with x = 0, 0.05, and 0.20 evaluated by the four-point probe method. The high resistivity value shows the predominance of the inter-grain part. The temperature dependence of the conductivity can be analyzed by variable range hopping model showing the charge carriers are formed by thermal activation. There is no superconducting behavior that could be observed in La2-xSrxCuO4 nanoparticles with x = 0.05 and 0.20.

VARIABLE RANGE HOPPING IN OXYGEN DEFICIENT YBa2Cu3Ox

1988 ◽  
Vol 02 (06) ◽  
pp. 1381-1386
Author(s):  
S. N. BHATIA ◽  
R. WALIA
Keyword(s):  
Thermoelectric Power ◽  
Variable Range Hopping ◽  
Variable Range ◽  
Hopping Model ◽  
Variable Range Hopping Model ◽  
Good Agreement

Our measurement of the resistivity and thermoelectric power from 20–300 K in the oxygen deficient YBa 2 Cu 3 O x annealed at 700, 800 and 850°C show good agreement with Mott's variable range hopping model below ~ 100 K.

Application of Variable Range Hopping Model to a Granular Carbon

2011 ◽  
Author(s):  
A. Aparecido-Ferreira ◽  
G. M. Ribeiro ◽  
E. S. Alves ◽  
J. F. Sampaio ◽  
Jisoon Ihm ◽  
...  
Keyword(s):  
Variable Range Hopping ◽  
Variable Range ◽  
Hopping Model ◽  
Variable Range Hopping Model

Investigation of Charge Transport in Amorphous Ge2Sb2Te5 Using the Variable-Range Hopping Model

2009 ◽  
Author(s):  
Enrico Piccinini ◽  
Fabrizio Buscemi ◽  
Thierry Tsafack ◽  
Massimo Rudan ◽  
Rossella Brunetti ◽  
...  
Keyword(s):  
Charge Transport ◽  
Variable Range Hopping ◽  
Variable Range ◽  
Hopping Model ◽  
Variable Range Hopping Model

Magnetic and electrical transport properties of Sr2Ti1−xCoxO4 ceramics by sol–gel

2017 ◽  
Vol 31 (17) ◽  
pp. 1750195
Author(s):  
Li Zhang ◽  
Yibao Li ◽  
Zhen Tang ◽  
Yan Deng ◽  
Hui Yuan ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Low Temperatures ◽  
Sol Gel ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Co Doping ◽  
Hopping Model ◽  
Variable Range Hopping Model ◽  
Co Doped

Microstructures, electrical transport and magnetic properties of Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics are investigated. With Co doping, the Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics remain tetragonal structure while the grain size is decreased with doping. Magnetic moment is enhanced with Co doping and ferromagnetism is observed at low temperatures for Co-doped Sr[Formula: see text]TiO[Formula: see text]. The Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] and Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] show semiconductor-like transport properties, which can be well fitted by Mott variable range hopping model. The results will provide an effective route to synthesize Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics as well as to investigate the physical properties.

STUDIES OF TRANSPORT PROPERTIES OF RFe1-xNixO3 (x ≤ 0.5) WHERE R = Nd, Sm AND Gd

2011 ◽  
Vol 25 (21) ◽  
pp. 1787-1794 ◽  
Author(s):  
ABIDA BASHIR ◽  
MOHD IKRAM ◽  
RAVI KUMAR
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Rare Earth Ion ◽  
Ni Substitution ◽  
Gap Parameter ◽  
Hopping Model ◽  
Variable Range Hopping Model ◽  
Semiconducting Behavior

We present here the electrical transport properties of RFe 1-x Ni x O 3 (x ≤ 0.5) where R = Nd , Sm and Gd and the correlation between these systems. The resistivity increases as the rare ion is changed from Nd to Sm . The resistivity increases from the magnitude of the order of 103 to 106 Ωcm at lower temperatures and from 10 to 105 Ωcm as the temperature is increased. Also, the resistivity decreases as the concentration of Ni is increased within the ensemble showing a semiconducting behavior. The resistivity data is fitted with the Greaves Variable Range Hopping model which fits in the intermediate range of temperatures. There is decrease in gap parameter, increase in conductivity and increase in the density of states at Fermi level which clarify that the correlation length in the conducting network increases with the increase in Ni substitution. The Debye temperature decreases as the Ni concentration increases and follows the same trend as the rare earth ion is replaced.

Influence of Mn Site Substitution on Electrical Resistivity and Magnetoresistance Properties of Rare Earth Manganite

2014 ◽  
Vol 1047 ◽  
pp. 123-129 ◽  
Author(s):  
Tejas M. Tank ◽  
D. Bhargava ◽  
V. Sridharan ◽  
S.S. Samatham ◽  
V. Ganesan ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Low Temperature ◽  
Charge Carriers ◽  
Variable Range Hopping ◽  
Density Of State ◽  
Spin Dependent Scattering ◽  
Hopping Model ◽  
Variable Range Hopping Model ◽  
Sn Substitution ◽  
Localization Of Charge Carriers

We investigate the effects of Cr, Ru and Sn substitution on electrical resistivity and magnetoresistance property of polycrystalline samples La0.67Sr0.33Mn1-xBxO3(x = 0, 0.05; B= Ru, Cr and Sn) compounds. The value of M-I transition temperature (TP) decreases while resistivity increases with Cr, Ru and Sn substitution, moreover, the largest low-temperature magnetoresistance (MR %) is found at magnetic field dependent (Isotherm), which suggest that the spin-dependent scattering from internal grain regions is also responsible for the low-temperature MR %. Resistivity data have been fitted with the variable range hopping model to estimate the density of state at Fermi level. It was observed that the substitution of various transition metals in the Mn-site leads to a decrease in conductivity of the doped manganite samples, with conduction being controlled by the disorder induced localization of charge carriers.

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