Abid Zaman | Riphah International University (original) (raw)

Papers by Abid Zaman

ACS Omega

This study reports the theoretical investigations on the structural, electronic, and optical prop... more This study reports the theoretical investigations on the structural, electronic, and optical properties of titanium-based fluoro-perovskites MTiF 3 (M = Cs and Rb) using density functional theory. The impact of on-site Coulomb interactions is considered, and calculations are performed in generalized gradient approximation with the Hubbard U term (GGA + U). The ground state parameters, such as lattice constants, bulk modulus, and pressure derivatives of bulk modulus, were found. These compounds are found stable in cubic perovskite structures having lattice constants of 4.30 and 4.38 Å for RbTiF 3 and CsTiF 3 , respectively. Analysis of elastic properties shows that both of the compounds are ductile in nature. According to the band structure profile, the examined compounds have a half-metallic character, exhibiting conducting behavior in the spin-up configuration and nonconducting behavior in the spin-down configuration. The ferromagnetic nature is conformed from the study of its magnetic moments. The optical behaviors such as reflectivity, absorption, refraction, and conductivity of the cubic phase of MTiF 3 (M = Rb and Cs) are studied in the energy range of 0−40 eV.

New Journal of Chemistry

Transition metal dichalcogenides (TMDs), such as rhenium diselenide, have currently attracted a l... more Transition metal dichalcogenides (TMDs), such as rhenium diselenide, have currently attracted a lot of attention as one of the novel candidates of the TMD family.

Journal of The Electrochemical Society

The hydrogen evolution reaction (HER) in renewable energy systems has long been a fascinating pro... more The hydrogen evolution reaction (HER) in renewable energy systems has long been a fascinating process, but designing highly efficient and ultrastable electrocatalysts is challenging. Transition metal-based heterostructure nanohybrids are currently drawing more interest in the field of electrolysis because nanohybids can optimize kinetic processes while simultaneously lowering charge transfer resistance and increasing the electrochemically active electrode’s surface area at the reaction interface. Here, we propose a concept for a two-step colloidal hot injection electrocatalyst based on NiSe/ReSe2 nanocomposites that is extremely effective for hydrogen evolution under acidic conditions. The as-obtained nanocomposite material worked efficiently, attaining a current density of 10 mA cm−2 at a substantially lower over-potential of 120 mV vs RHE as compared to each of the individual components i.e. NiSe nanoparticles and ReSe2 nanosheets. As single component catalysts, ReSe2 nanosheets a...

Micromachines

In contrast to austenitic and martensitic stainless steels, ferritic stainless steels have a lowe... more In contrast to austenitic and martensitic stainless steels, ferritic stainless steels have a lower hardness and wear resistance but exhibit excellent corrosion resistance. Due to this fact, their use in the aerospace, automobile, and house construction industries is restricted. Several methods have been utilized to enhance the tribological characteristics of ferritic stainless steels. In this work, titanium nitride coating has been carried out by using a cathodic cage of titanium material, and later on, the titanium cathodic cage is replaced by an AISI-304 cathodic cage in a CCPN chamber to form iron nitride coating on AISI-430 ferritic stainless steel coupons through a plasma nitriding process for 4 h at a fixed temperature of 400 °C. The microstructures and mechanical traits of all processed and control coupons were analyzed using scanning electron microscopy, X-ray diffraction, ball-on-disc wear tester, and microhardness tester techniques. The results showed that hardness increas...

Micromachines

Low loss Ruddlesden–Popper (RP) series, i.e., (Sr1−xCax)5Ti4O13, 0.0 ≤ x ≤ 0.06, has been synthes... more Low loss Ruddlesden–Popper (RP) series, i.e., (Sr1−xCax)5Ti4O13, 0.0 ≤ x ≤ 0.06, has been synthesized by a mixed oxide route. In this work, the substitution of Ca2+ cation in Sr5Ti4O13 sintered ceramics was chosen to enhance the structural, optical, and dielectric properties of the product. It was found that the Ca2+ content has significant effects on enhancing the dielectric properties as compared to Mn and glass additions. It was observed that the relative density, band gap energy, and dielectric loss (tangent loss) increase while relative permittivity decreases along with Ca2+ content. High relative density (96.7%), low porosity, and high band gap energy (2.241 eV) values were obtained in (Sr1−xCax)5Ti4O13, 0.0 ≤ x ≤ 0.06 sintered ceramics. These results will play a key role in the application of dielectric resonators.

RSC Advances

In this work, the structural, electronic, magnetic and elastic properties of the xenon-based fluo... more In this work, the structural, electronic, magnetic and elastic properties of the xenon-based fluoroperovskites XeMF3 (M = Ti, V, Zr, Nb) have been studied using density functional theory.

Journal of Materials Research and Technology

First-principles investigation on the structural, electronic, vibrational and magnetic properties... more First-principles investigation on the structural, electronic, vibrational and magnetic properties of the Co-substituted orthorhombic SrSnO 3 ,

Iranian Journal of Science and Technology, Transactions A: Science, 2020

High-Q Li 2 Mg x TiO 3+x (2.2 ≤ x ≤ 4) microwave dielectric ceramics were fabricated by using a c... more High-Q Li 2 Mg x TiO 3+x (2.2 ≤ x ≤ 4) microwave dielectric ceramics were fabricated by using a conventional solid-state reaction method followed by laminated sintering technique. All samples showed clear and smooth grains through this sintering method. The XRD patterns indicated that Li 2 Mg x TiO 3+x (2.2 ≤ x ≤ 4) ceramics displayed MgO-like cubic phase with ordered rock salt structure. The dielectric constant decreased monotonically because the molar volume expanded and molecular polarizability decreased when x values increased. The Q × f values of Li 2 Mg x TiO 3+x (2.2 ≤ x ≤ 4) ceramics were dependent significantly on both average grain sizes and packing fraction. The Li 2 Mg 3.6 TiO 6.6 ceramics sintered at 1375°C had excellent microwave dielectric properties of ε r ∼ 12.7, Q × f ∼ 169,000 GHz, τ f ∼ −32.8 ppm/°C.

Crystals

In the present work, pure and Cr-doped MoO3 microrods were successfully prepared through the sol ... more In the present work, pure and Cr-doped MoO3 microrods were successfully prepared through the sol gel auto combustion method. The phase evaluation and microstructural, dielectric, and optical properties of synthesized samples were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and an impedance analyzer (1 MHz–3 GHz). All the samples showed hexagonal structure with space group (P63). According to Vegard’s law, lattice parameters increase with the increase in chromium (Cr3+) contents. In addition, the Williamson–Hall (W–H) plot was drawn for evaluating the micro-strain (εW-H) and crystallite size (DW-H) parameters. From microstructural analysis it was found that the size of microrods increased along with Cr3+ contents. Decreasing band gap energy was observed (from 2.98 to 2.71 eV) with increasing Cr3+ contents. The variation of the dielectric constant and tangent loss of MoO3 microrods with respect to frequency w...

Physica Scripta

Copper based halide-perovskites ACuF3 (A = Mg and Ca) have been studied for potential application... more Copper based halide-perovskites ACuF3 (A = Mg and Ca) have been studied for potential application as an electrode material. Structural, electronic, elastic and optical properties of these compounds are investigated by utilizing the wien2k code within density functional theory. Structural study reveal that both compounds have stable and cubic perovskite structure with optimized lattice constants 4.07 Å and 4.15 Å having space group pm-3m 221. Electronic analysis reveals that both compounds have metallic nature. Through IR-Elast package the elastic constants are evaluated and by utilizing these constant various elastic parameters like bulk modulus, shear modulus, Kleinman parameter, Anistropic factor are analyzed. Both compounds are found to be mechanically stable with ductile nature. Furthermore, the various optical parameters such as dielectric function, refractive index, optical conductivity, reflectivity and absorption coefficient are studied. The seebeck coefficient, electrical c...

Journal of Superconductivity and Novel Magnetism

Journal of the Physical Society of Japan, May 15, 2022

ACS Omega

Multilayer CdZnS (CZS) thin film was deposited on soda lime glass substrates. After deposition, t... more Multilayer CdZnS (CZS) thin film was deposited on soda lime glass substrates. After deposition, the films were vacuum and air annealed at 100°C, 200°C, 300 and 400°C for 1 h. Effects of vacuum and air annealing on structural, morphological, optical, and electrical properties of multilayer CZS films with increasing annealing temperature (IAT) were studied. The structural analysis revealed that the films were polycrystalline with hexagonal structure having a prominent/intensive peak along the (002) plane at 300 and 400°C. The crystallite size of nanoparticles increased from 18.4 to 20.5 nm under air annealing and from 18.4 to 26.9 nm under vacuum annealing, showing the significance of annealing on nanoparticle grain growth. According to morphological analysis, the multilayer technique provides homogeneous film distribution over the substrate. The transmittance graphs of films revealed that it increased up to 92% in the visible and NIR regions under vacuum annealing and up to 52% under air annealing. Vacuum annealing enhanced the band gap energies more significantly than air annealing. The electrical resistivity increased with IAT, showing that structural, morphological, optical, and electrical properties of the multilayer thin films of CZS were strongly dependent on vacuum and air annealing.

Journal of Basic & Applied Sciences, 2022

In this study, lead-free Ba-doped ((Bi(0.5)Na0.5)TiO3 ceramics were synthesized by the convention... more In this study, lead-free Ba-doped ((Bi(0.5)Na0.5)TiO3 ceramics were synthesized by the conventional solid-state reaction method and characterized by X-ray diffraction technique, which indicates the pure crystalline nature of ceramics with ABO3 symmetry. The splitting in the peaks reveals that the ceramics with x = 0.10 and 0.30 are well in Morphotrophic Phase Boundary where rhombohedral and tetragonal phases co-exist. The scanning electron microscope images show that the average grain size of the ceramics increases with an increase in the Ba concentration. Dielectric properties of pure and Ba-doped ((Bi(0.5)Na0.5)TiO3ceramics measured by LCR meter in the frequency range of 1 k Hz – 1 M Hz shows the decrease in the value of dielectric constant with an increase in frequency. εmax = 5563 was obtained at x = 0.30 with TC = 300 °C at the frequency of 1 k Hz, whereas σ (f) curves were found to be merging at a high value of frequency and temperature regions.

Arabian Journal of Chemistry, 2022

ACS Omega, 2022

The lead-free Ca(Sn x Ti 1−x)O 3 , (0 ≤ x ≤ 0.8) sample has been successfully prepared through th... more The lead-free Ca(Sn x Ti 1−x)O 3 , (0 ≤ x ≤ 0.8) sample has been successfully prepared through the ball milling process, sintered at 1200°C for 3 h. The structural, morphological, vibrational, and microwave dielectric properties of synthesized samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and impedance analysis. All the samples have an orthorhombic phase structure with a space group of Pbnm formation, and the crystalline size and strain changes with respect to Sn 4+ doping were observed in the XRD analysis. From a morphological point of view, on increasing the content "x", the grain size reduces from 3.29 to 1.37 μm. The existence of vibrations and the bridging stretching mode of Ti−O−Ti and Ti− O−Sn both are associated with the broadband in the region below 800 cm −1 verified by FT-IR. The variation in electrons hopping off the host compound with respect to Sn 4+ ions was analyzed in AC conductivity. The changes of dielectric properties such as complex permittivity, modulus spectroscopy, and dielectric loss at room temperature with a different frequency range of 1.00−2.00 GHz are discussed.

Calcium Titanium Oxide or Calcium Titanate (CaTiO 3-CT) and Zinc doped calcium titanium oxide (Ca... more Calcium Titanium Oxide or Calcium Titanate (CaTiO 3-CT) and Zinc doped calcium titanium oxide (Ca1-xZnxTiO 3-CT:Zn) Powder in a concentration of (0 ≤ x ≤ 0.5 molar ration of Zinc) were obtained by a simple method called solid-state reaction. Ceramics are based on CaTiO 3-CT and (Ca 0.5 Zn 0.5) TiO 3 solid solutions synthesized and characterized in order to study microwave dielectric properties. X-ray spectra analysis, FT-IR Spectra, and SEM studies shown that the synthesized powders were contained nano-crystallite shape are Orthorhombic. The suitable shift in the XRD peaks for x=0.5 composition towards comparatively lower angles gradually with the increase of "x" values, which indicates that the lattice parameters of Ca1-xZnxTiO 3 decreases after Original Research Article

ACS Omega

This study reports the theoretical investigations on the structural, electronic, and optical prop... more This study reports the theoretical investigations on the structural, electronic, and optical properties of titanium-based fluoro-perovskites MTiF 3 (M = Cs and Rb) using density functional theory. The impact of on-site Coulomb interactions is considered, and calculations are performed in generalized gradient approximation with the Hubbard U term (GGA + U). The ground state parameters, such as lattice constants, bulk modulus, and pressure derivatives of bulk modulus, were found. These compounds are found stable in cubic perovskite structures having lattice constants of 4.30 and 4.38 Å for RbTiF 3 and CsTiF 3 , respectively. Analysis of elastic properties shows that both of the compounds are ductile in nature. According to the band structure profile, the examined compounds have a half-metallic character, exhibiting conducting behavior in the spin-up configuration and nonconducting behavior in the spin-down configuration. The ferromagnetic nature is conformed from the study of its magnetic moments. The optical behaviors such as reflectivity, absorption, refraction, and conductivity of the cubic phase of MTiF 3 (M = Rb and Cs) are studied in the energy range of 0−40 eV.

New Journal of Chemistry

Transition metal dichalcogenides (TMDs), such as rhenium diselenide, have currently attracted a l... more Transition metal dichalcogenides (TMDs), such as rhenium diselenide, have currently attracted a lot of attention as one of the novel candidates of the TMD family.

Journal of The Electrochemical Society

The hydrogen evolution reaction (HER) in renewable energy systems has long been a fascinating pro... more The hydrogen evolution reaction (HER) in renewable energy systems has long been a fascinating process, but designing highly efficient and ultrastable electrocatalysts is challenging. Transition metal-based heterostructure nanohybrids are currently drawing more interest in the field of electrolysis because nanohybids can optimize kinetic processes while simultaneously lowering charge transfer resistance and increasing the electrochemically active electrode’s surface area at the reaction interface. Here, we propose a concept for a two-step colloidal hot injection electrocatalyst based on NiSe/ReSe2 nanocomposites that is extremely effective for hydrogen evolution under acidic conditions. The as-obtained nanocomposite material worked efficiently, attaining a current density of 10 mA cm−2 at a substantially lower over-potential of 120 mV vs RHE as compared to each of the individual components i.e. NiSe nanoparticles and ReSe2 nanosheets. As single component catalysts, ReSe2 nanosheets a...

Micromachines

In contrast to austenitic and martensitic stainless steels, ferritic stainless steels have a lowe... more In contrast to austenitic and martensitic stainless steels, ferritic stainless steels have a lower hardness and wear resistance but exhibit excellent corrosion resistance. Due to this fact, their use in the aerospace, automobile, and house construction industries is restricted. Several methods have been utilized to enhance the tribological characteristics of ferritic stainless steels. In this work, titanium nitride coating has been carried out by using a cathodic cage of titanium material, and later on, the titanium cathodic cage is replaced by an AISI-304 cathodic cage in a CCPN chamber to form iron nitride coating on AISI-430 ferritic stainless steel coupons through a plasma nitriding process for 4 h at a fixed temperature of 400 °C. The microstructures and mechanical traits of all processed and control coupons were analyzed using scanning electron microscopy, X-ray diffraction, ball-on-disc wear tester, and microhardness tester techniques. The results showed that hardness increas...

Micromachines

Low loss Ruddlesden–Popper (RP) series, i.e., (Sr1−xCax)5Ti4O13, 0.0 ≤ x ≤ 0.06, has been synthes... more Low loss Ruddlesden–Popper (RP) series, i.e., (Sr1−xCax)5Ti4O13, 0.0 ≤ x ≤ 0.06, has been synthesized by a mixed oxide route. In this work, the substitution of Ca2+ cation in Sr5Ti4O13 sintered ceramics was chosen to enhance the structural, optical, and dielectric properties of the product. It was found that the Ca2+ content has significant effects on enhancing the dielectric properties as compared to Mn and glass additions. It was observed that the relative density, band gap energy, and dielectric loss (tangent loss) increase while relative permittivity decreases along with Ca2+ content. High relative density (96.7%), low porosity, and high band gap energy (2.241 eV) values were obtained in (Sr1−xCax)5Ti4O13, 0.0 ≤ x ≤ 0.06 sintered ceramics. These results will play a key role in the application of dielectric resonators.

RSC Advances

In this work, the structural, electronic, magnetic and elastic properties of the xenon-based fluo... more In this work, the structural, electronic, magnetic and elastic properties of the xenon-based fluoroperovskites XeMF3 (M = Ti, V, Zr, Nb) have been studied using density functional theory.

Journal of Materials Research and Technology

First-principles investigation on the structural, electronic, vibrational and magnetic properties... more First-principles investigation on the structural, electronic, vibrational and magnetic properties of the Co-substituted orthorhombic SrSnO 3 ,

Iranian Journal of Science and Technology, Transactions A: Science, 2020

High-Q Li 2 Mg x TiO 3+x (2.2 ≤ x ≤ 4) microwave dielectric ceramics were fabricated by using a c... more High-Q Li 2 Mg x TiO 3+x (2.2 ≤ x ≤ 4) microwave dielectric ceramics were fabricated by using a conventional solid-state reaction method followed by laminated sintering technique. All samples showed clear and smooth grains through this sintering method. The XRD patterns indicated that Li 2 Mg x TiO 3+x (2.2 ≤ x ≤ 4) ceramics displayed MgO-like cubic phase with ordered rock salt structure. The dielectric constant decreased monotonically because the molar volume expanded and molecular polarizability decreased when x values increased. The Q × f values of Li 2 Mg x TiO 3+x (2.2 ≤ x ≤ 4) ceramics were dependent significantly on both average grain sizes and packing fraction. The Li 2 Mg 3.6 TiO 6.6 ceramics sintered at 1375°C had excellent microwave dielectric properties of ε r ∼ 12.7, Q × f ∼ 169,000 GHz, τ f ∼ −32.8 ppm/°C.

Crystals

In the present work, pure and Cr-doped MoO3 microrods were successfully prepared through the sol ... more In the present work, pure and Cr-doped MoO3 microrods were successfully prepared through the sol gel auto combustion method. The phase evaluation and microstructural, dielectric, and optical properties of synthesized samples were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and an impedance analyzer (1 MHz–3 GHz). All the samples showed hexagonal structure with space group (P63). According to Vegard’s law, lattice parameters increase with the increase in chromium (Cr3+) contents. In addition, the Williamson–Hall (W–H) plot was drawn for evaluating the micro-strain (εW-H) and crystallite size (DW-H) parameters. From microstructural analysis it was found that the size of microrods increased along with Cr3+ contents. Decreasing band gap energy was observed (from 2.98 to 2.71 eV) with increasing Cr3+ contents. The variation of the dielectric constant and tangent loss of MoO3 microrods with respect to frequency w...

Physica Scripta

Copper based halide-perovskites ACuF3 (A = Mg and Ca) have been studied for potential application... more Copper based halide-perovskites ACuF3 (A = Mg and Ca) have been studied for potential application as an electrode material. Structural, electronic, elastic and optical properties of these compounds are investigated by utilizing the wien2k code within density functional theory. Structural study reveal that both compounds have stable and cubic perovskite structure with optimized lattice constants 4.07 Å and 4.15 Å having space group pm-3m 221. Electronic analysis reveals that both compounds have metallic nature. Through IR-Elast package the elastic constants are evaluated and by utilizing these constant various elastic parameters like bulk modulus, shear modulus, Kleinman parameter, Anistropic factor are analyzed. Both compounds are found to be mechanically stable with ductile nature. Furthermore, the various optical parameters such as dielectric function, refractive index, optical conductivity, reflectivity and absorption coefficient are studied. The seebeck coefficient, electrical c...

Journal of Superconductivity and Novel Magnetism

Journal of the Physical Society of Japan, May 15, 2022

ACS Omega

Multilayer CdZnS (CZS) thin film was deposited on soda lime glass substrates. After deposition, t... more Multilayer CdZnS (CZS) thin film was deposited on soda lime glass substrates. After deposition, the films were vacuum and air annealed at 100°C, 200°C, 300 and 400°C for 1 h. Effects of vacuum and air annealing on structural, morphological, optical, and electrical properties of multilayer CZS films with increasing annealing temperature (IAT) were studied. The structural analysis revealed that the films were polycrystalline with hexagonal structure having a prominent/intensive peak along the (002) plane at 300 and 400°C. The crystallite size of nanoparticles increased from 18.4 to 20.5 nm under air annealing and from 18.4 to 26.9 nm under vacuum annealing, showing the significance of annealing on nanoparticle grain growth. According to morphological analysis, the multilayer technique provides homogeneous film distribution over the substrate. The transmittance graphs of films revealed that it increased up to 92% in the visible and NIR regions under vacuum annealing and up to 52% under air annealing. Vacuum annealing enhanced the band gap energies more significantly than air annealing. The electrical resistivity increased with IAT, showing that structural, morphological, optical, and electrical properties of the multilayer thin films of CZS were strongly dependent on vacuum and air annealing.

Journal of Basic & Applied Sciences, 2022

In this study, lead-free Ba-doped ((Bi(0.5)Na0.5)TiO3 ceramics were synthesized by the convention... more In this study, lead-free Ba-doped ((Bi(0.5)Na0.5)TiO3 ceramics were synthesized by the conventional solid-state reaction method and characterized by X-ray diffraction technique, which indicates the pure crystalline nature of ceramics with ABO3 symmetry. The splitting in the peaks reveals that the ceramics with x = 0.10 and 0.30 are well in Morphotrophic Phase Boundary where rhombohedral and tetragonal phases co-exist. The scanning electron microscope images show that the average grain size of the ceramics increases with an increase in the Ba concentration. Dielectric properties of pure and Ba-doped ((Bi(0.5)Na0.5)TiO3ceramics measured by LCR meter in the frequency range of 1 k Hz – 1 M Hz shows the decrease in the value of dielectric constant with an increase in frequency. εmax = 5563 was obtained at x = 0.30 with TC = 300 °C at the frequency of 1 k Hz, whereas σ (f) curves were found to be merging at a high value of frequency and temperature regions.

Arabian Journal of Chemistry, 2022

ACS Omega, 2022

The lead-free Ca(Sn x Ti 1−x)O 3 , (0 ≤ x ≤ 0.8) sample has been successfully prepared through th... more The lead-free Ca(Sn x Ti 1−x)O 3 , (0 ≤ x ≤ 0.8) sample has been successfully prepared through the ball milling process, sintered at 1200°C for 3 h. The structural, morphological, vibrational, and microwave dielectric properties of synthesized samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and impedance analysis. All the samples have an orthorhombic phase structure with a space group of Pbnm formation, and the crystalline size and strain changes with respect to Sn 4+ doping were observed in the XRD analysis. From a morphological point of view, on increasing the content "x", the grain size reduces from 3.29 to 1.37 μm. The existence of vibrations and the bridging stretching mode of Ti−O−Ti and Ti− O−Sn both are associated with the broadband in the region below 800 cm −1 verified by FT-IR. The variation in electrons hopping off the host compound with respect to Sn 4+ ions was analyzed in AC conductivity. The changes of dielectric properties such as complex permittivity, modulus spectroscopy, and dielectric loss at room temperature with a different frequency range of 1.00−2.00 GHz are discussed.

Calcium Titanium Oxide or Calcium Titanate (CaTiO 3-CT) and Zinc doped calcium titanium oxide (Ca... more Calcium Titanium Oxide or Calcium Titanate (CaTiO 3-CT) and Zinc doped calcium titanium oxide (Ca1-xZnxTiO 3-CT:Zn) Powder in a concentration of (0 ≤ x ≤ 0.5 molar ration of Zinc) were obtained by a simple method called solid-state reaction. Ceramics are based on CaTiO 3-CT and (Ca 0.5 Zn 0.5) TiO 3 solid solutions synthesized and characterized in order to study microwave dielectric properties. X-ray spectra analysis, FT-IR Spectra, and SEM studies shown that the synthesized powders were contained nano-crystallite shape are Orthorhombic. The suitable shift in the XRD peaks for x=0.5 composition towards comparatively lower angles gradually with the increase of "x" values, which indicates that the lattice parameters of Ca1-xZnxTiO 3 decreases after Original Research Article