Dependence of Electrical and Thermal Properties on Applied Electric Field in La Doped Barium Titanate Displacive Ferroelectric Perovskites
Dushyant Pradeep,
Jagdev Singh
Issue:
Volume 5, Issue 2, December 2021
Pages:
30-36
Received:
6 April 2021
Accepted:
12 May 2021
Published:
31 August 2021
DOI:
10.11648/j.cm.20210502.11
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Abstract: The high dielectric constant and low dielectric loss are the most desirable characteristics of the dielectric materials. Considering the hazardous nature of lead-based ceramics, many research groups have paid great attention to the research on non-lead-based perovskites. The effect of the electric field on the electrical and thermal properties of the Lanthanum doped barium Titanate, one of the main important members of the ferroelectric Perovskites family is studied using the method of double time thermal Green’s function and Kubo formalism. With the help of the Silverman-Joseph Hamiltonian a general expression is derived. The electric field and temperature dependent dielectric constant and specific heat capacity of Ba1-xLaxTiO3 crystal has been investigated. The dielectric constant decreases with increase in temperature and applied electric field component. The variation shows a consequence of the gradual decrease in the Curie temperature of the doped material with the increase in defect concentrations. The results also compared with some previous studies done by the author and other workers on similar other materials.
Abstract: The high dielectric constant and low dielectric loss are the most desirable characteristics of the dielectric materials. Considering the hazardous nature of lead-based ceramics, many research groups have paid great attention to the research on non-lead-based perovskites. The effect of the electric field on the electrical and thermal properties of t...
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Stabilization of Black Cotton Soil Using Various Admixtures: A Review
Umar Yerima Mai-Bade,
Adamu Umar Chinade,
Ahmad Batari,
Saeed Modibbo Saeed
Issue:
Volume 5, Issue 2, December 2021
Pages:
37-45
Received:
15 August 2021
Accepted:
22 September 2021
Published:
24 November 2021
DOI:
10.11648/j.cm.20210502.12
Downloads:
Views:
Abstract: This paper reviews the effect of various admixtures in view of increasing strength and reducing deformation characteristics of black cotton soil from studies carried out by different researchers. Stabilization of black cotton soil is targeted at providing stable and durable engineering structures. It becomes necessary when materials intended for foundation and pavement construction failed to meet the requirement in civil engineering practice. Black cotton soil from north-eastern part of Nigeria and different locations around the world are mostly classified as A-7-6 soils by American Association of State Highway and Transportation Officials (AASHTO); CH high plasticity clay soils by Unified Soil Classification System (UCSC) and high swell potential BCS by Nigerian Building and Road Research Institute (NBRRI). Experiment conducted include; Atterberg’s Limits, Specific Gravity, Sieve/hydrometer Analysis, Free Swell, Compaction, Triaxial, Shear Box, Unconfined Compressive Strength (UCS), and California Bearing Ratio (CBR) tests. Soil characteristics such as the maximum dry density (MDD), optimum moisture content (OMC), CBR values, shear strength, cohesion, and angle of internal friction were improved significantly by admixtures such as lime, cement, E-waste, reclaimed asphalt pavement, and steel mill ore, while admixtures such as groundnut ash, bagasse ash and plantain peel powder demonstrated unsatisfactory improvement when used as standalone. Thus, it can be concluded that black cotton soil when stabilized with admixtures such as lime, cement, reclaimed asphalt pavement, E-waste, and still mill ore can be used in foundation and pavement construction. This study finally recommends the supplementary use of weak admixtures with some rather cementitious material to achieve a strong and durable foundation.
Abstract: This paper reviews the effect of various admixtures in view of increasing strength and reducing deformation characteristics of black cotton soil from studies carried out by different researchers. Stabilization of black cotton soil is targeted at providing stable and durable engineering structures. It becomes necessary when materials intended for fo...
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