Nickel ferrite thin films were synthesized by pulsed laser deposition. It was determined that the monotonic increase in saturation magnetization and the non-monotonic increase in electrical conductivity depend on the oxygen partial pressure during the growth of the thin films. A substantial reduction in magnetization was found which ranged between 0.4% and 40% of the bulk value as the oxygen partial pressure increased from 0.2 × 10−6 Torr to 500 mTorr during the deposition of the films. There was a three orders of magnitude increase in conductivity for the sample prepared under the most oxygen deficient environment (partial pressure of oxygen 0.2 × 10−6 Torr). These variations in saturation magnetization and conductivity are described within the framework of cation/oxygen vacancies in an inverse spinel nickel ferrite structure. The changes in the electronic structure due to the presence of the vacancies were investigated using x-ray photoelectron spectroscopy, which confirmed the formation of lower valent Ni for the samples prepared in an oxygen deficient atmosphere.

The e-commerce market of Pakistan has phenomenally fostered in recent years as a result of cyberspace expansion and launching of various national and international vendors. While country’s e-commerce scenario has significantly reshaped, customers are still reluctant to adopt e-payment methods and cash on delivery (COD) prevails as the method of payments for online shopping. This study was conducted to empirically investigate major factors which influence Pakistani customers to opt for COD while shopping online. A framework was proposed based on seven constructs and the data were collected using 5-point Likert-type scale. Statistical Package for the Social Sciences (SPSS) v. 22 and Amos v. 23 were used for statistical analysis and structural equation modeling (SEM). Cronbach’s alpha values above .85 were found suggesting good internal consistency. The goodness-of-fit index and adjusted goodness-of-fit index values were observed to be 0.933 and 0.866, respectively. In SEM analysis, perceived security against online scams and perceived control over the buying process were observed to be the key role players instigating Pakistani customers to use COD. Interestingly, perceived trust and perceived satisfaction did not show significant impact. Moreover, the moderator of ease of use positively mediated the influence of perceived security on the use of COD. This study presents imperative implications for online businesses as well as government agencies. The investigation provides an insight into purchase behaviors of Pakistani e-customers and has paramount importance for e-commerce retailers and marketing startups in evolving e-commerce scenario of the country.

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A series of copper substituted cobalt chromium ferrites, Cu x Co 1 − x Cr 0.5 Fe 1.5 O 4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) has been synthesized, by employing powder metallurgy method. Calcination of the samples has been carried out for 24 hours at 1100°C. The resultant materials have been investigated by using a variety of techniques, including X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM)), scanning electron microscopy (SEM), and ultraviolet visible spectroscopy (UV-Vis). The XRD patterns confirmed that all compositions had a cubic spinel structure with a single phase and the lattice parameter was found to increase with increasing copper concentration. FT-IR spectroscopy has been used for studying the chemical bonds in the spinel ferrite. Shifting of the bands υ 1 and υ 2 has been observed. It has been revealed from VSM analysis that saturation magnetization and coercivity decrease with rising the Cu +2 doping. Magnetic properties have been explained on the basis of cation distribution. Scanning electron microscopy (SEM) has been used to study the surface morphology of prepared samples. UV-Vis analysis revealed the optical absorption of the samples. An increase in band gaps has been observed with increasing copper concentration in the sample.

Optical emission spectra of a laser induced plasma of vanadium pentoxide (V2O5) using a Nd:YAG laser (1064 nm, 10 ns) in the presence and absence of the magnetic field of 0.45 T have been investigated. The effect of the magnetic field (B) on the V2O5 plasma at various laser irradiances ranging from 0.64 GW cm−2 to 2.56 GW cm−2 is investigated while keeping the pressure of environmental gases of Ar and Ne constant at 100 Torr. The magnetic field effect on plasma parameters of V2O5 is also explored at different delay times ranging from 0 μs to 10 μs for both environmental gases of Ar and Ne at the laser irradiance of 1.28 GW cm−2. It is revealed that both the emission intensity and electron temperature of the vanadium pentoxide plasma initially increase with increasing irradiance due to the enhanced energy deposition and mass ablation rate. After achieving a certain maximum, both exhibit a decreasing trend or saturation which is attributable to the plasma shielding effect. However, the electron density shows a decreasing trend with increasing laser irradiance. This trend remains the same for both cases, i.e., in the presence and in the absence of magnetic field and for both background gases of Ar and Ne. However, it is revealed that both the electron temperature and electron density of the V2O5 plasma are significantly enhanced in the presence of the magnetic field for both environments at all laser irradiances and delay times, and more pronounced effects are observed at higher irradiances. The enhancement in plasma parameters is attributed to the confinement as well as Joule heating effects caused by magnetic field employment. The confinement of the plasma is also confirmed by the analytically calculated value of magnetic pressure β, which is smaller than plasma pressure at all irradiances and delay times, and therefore confirms the validity of magnetic confinement of the V2O5 plasma.

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