Incongruity in Contemporary and Shariah Compliant Current Accounts and Ijarah Operated by Islamic Banking

Current accounts and Ijarah has been foremost and important tools operated by the Islamic Financial Institutions. This study attempts to explore a few misgivings in the handling of current accounts by the Islamic banks in Pakistan. Financial management of Islamic banks is not under consideration which leads to the violation of Shariah’s fundamentals. Also in case of Ijarah, a bank’s client suffers from financial losses which must be borne in Islamic Banking system. Islamic Banks transfer the burden of some charges emerging form ownership of leased asset on their clientele which does not have any justification according to Shariah. This research has been carried out by taking unstructured interviews from some of the concerned staff of Islamic Banks. The results depict that current accounts and Ijarah is in operation and need to be revised and refined and must comply with Shariah.

Synthesis and Characterization of Multidimensional Co and Fe Based Ferromagnetic Nanostructures

The spintronics is the developing and motivating research area that enhanced the efficiency of conventional electronics devices by the addition of spin degree of freedom such as; to decrease the consumption of electric power, improve the speed of data processing and enhance the integrated densities.This research focuses the physical and structural properties of quaternary full Heusler and binary (magnetic-nonmagnetic) alloys in the field of spintronics. As Heusler alloy nanowires (NWs) is a young research field, therefore the majority research focuses on their synthesis, magnetic properties and structural properties. The main issue is the size dependent structure, transition of phase, spin and magnetic related properties are open for the wide range of research. In the last few decades, Heusler (Half Heusler/full Heusler) family produced the revolutionary effect towards spintronics or magneto-electronics with large Curie temperature, especially at the nanoscale. The spin polarized current showed maximum value due to gap at Fermi level (100% spin-polarization) that increased the efficiency of magnetoelectronic devices. Among all, several alloys of Heusler family behave like half-metals. The shape anisotropy in the ferromagnetic nanostructure especially in Heusler alloys is required presently as well as in future spintronics devices.For such reason, the research has been directed towards the quaternary (full Heusler alloy) half-metallic ferromagnetism and binary alloy (Ferrononferro coupling) to open the new way to fulfill the requirements of present and future prospectus. Full Heusler alloys, called quaternary i.e X2YZ (2:1:1), where Z and (X & Y) belongs to transition and main group element respectively. And the structure of such a Heusler family is characterized through L21. Presently, cobalt and iron-based full-Heusler alloys focus their attention in spintronics based devices such as magnetoresistance (MR), giant magnetoresistance (GMR) and tunneling magnetoresistance (TMR) and provide maximum stability due to half-metallic nature. The Co-based Co2Mn0.5Fe0.5Sn full Heusler alloy NWs were synthesized through alternating current (AC) electrochemical deposition (ECD) in anodized aluminum oxide (AAO) templates. To approach the required results, homemade AAO templates were synthesized by two-step anodization in 5 % H3PO4 solution using 60 V at constant DC source at temperature range 1 to 5 ºC. Achieving the desired structure of full Heusler (L21) alloys NWs became possible in electrochemically by changing the AC- deposition potential from 10 to 18V by the 2V difference. The origin of band gap at Fermi level confirmed the half metallic character(100% spin polarization), thathas been measured through density functional theory (DFT) by using WIEN2k programs of full potential linearized augmented plane wave (FP-LAPW) technique. The diameter of the AAO templates and NWs was found in the range of 55 to 65nm that is confirmed from scanning electron microscope (SEM) in all synthesized Heusler alloy and binary alloy NWs. The formation of partial disorder (B2-type), full disorder (A2-type) and full order (L21) structure of Co2Mn0.5Fe0.5Sn full Heusler alloy is confirmed through X-rays diffraction (XRD) analysis that has been measured in anodic alumina along with substrate of aluminum. Hence at 16V and 18V, the presence of fundamental, even and odd supper lattice peaks confirmed the full order (L21) structure of Co2Mn0.5Fe0.5Sn full Heusler alloy NWs. The deposition of Co, Mn & Fe increases with increase in deposition voltage, whereas Sn shows decreasing order, which implies that each element has different reduction potential. The electrical measurement was examined without AAO templates, the resistivity shows decreasing order (from 160 to 40 Ωcm) to that of mobility shows opposite fashion (28 to 358 cm2/Vs) with respect to increasing in deposition potential. It means that our sample is a metallic character which reduces the electron grain boundary dispersal and a boost of the grain size. The magnetic properties illustrate that coercivity shows sharp increment (from 65 to 245Oe) at 18V owing the formation of fully order (L21) structure of Co2Mn0.5Fe0.5Sn full Heusler alloy NWs. Fe-based Fe2CoSn full Heusler alloy NWs has been synthesized with the same approach, as AC- deposition potential has taken from 9 to 17V by the increment of 2V to achieve the desired results of L21 structure with a combination of 2:1:1 ratio. The influence of deposition voltage on chemical composition, electric/magnetic properties, morphology and crystal structure is studied. The half-metallic ferromagnetism in Fe2CoSn Haussler alloy NWs is investigated by using the FP-LAPW technique to resolve the Kohn-Sham equations executing WIEN2k program. Hence, the spin polarization, partial density of states (PDOS) shows that at Fermi level few states of Fe-3d exist. Though the states are very minor and contribute very minute in conduction, related to the minority channel. Secondly, such alloy obeys Slater-Pauling rule, in which total spin magnetic moment directly proportional to the electrons of valance shell in the unit cell of Fe2CoSn Haussler alloy NWs. XRD measurement of such NWs reflects (311) peak through all samples that related to the substrate of aluminum. The peaks of fundamental, odd and even supper lattice have been observed all together in 15V and 17V. It confirmed the full order structure (L21) of Fe2CoSn Heusler alloy NWs. Below which, A2 and B2-type disorder structure have been synthesized. Besides these, variation and Shift are observed in the intensity of diffraction peaks, that shows the influence of deposition voltage on composition, the order of chemical structure and lattice constant. The increment of the grain size shows the maximum result with the formation of L21 Heusler structure. With such specific structure of Fe2CoSn Heusler alloy NWs, the M-H loops demonstrate that coercivity attained maximum value (484 Oe) at 17V by making some defects that divide such NWs into tiny magnetics, causing the rise in magneto-crystalline anisotropy and blocking the domain walls. The non-ohmic behavior is taken from two probes (I-V) technique whereas Fe2CoSn Heusler alloy NWs with L21 structure followed the excellent spin-dependent function.Ferromagnetic NWs such as Fe or Co are precise class that can be used in long range application particularly, in data-storage devices, magneto-resistive sensors and spin dependent devices. The properties of such devices directly related to the morphology and composition parameters. Therefore, to enhance the function of such devices, the ferromagnetic (Fe or Co) make alloy NWs with nonmagnetic element such Cu or Mn to form Fe-Cu or Fe-Mn were also synthesized. The advantage of such alloy NWs is that it can tune the magnetic and transport parameters through morphology and composition ratio. Today the active research material i.e copper (Cu) has large surface activity, good biocompatibility and excellent conduction and physicochemical properties. To enhance the function of the magnetic, electronic and medical application, nonmagnetic-ferromagnetic is added such as corporate FeCu in nanodevices. Hence, the Fe100─XCuX alloy NWs have been synthesized with the same above approach. Only deposition potential (16V) remained constant and the concentration of Fe-Cu in the electrolyte solution is changed. The XRD pattern analysis confirms that initially, the peaks of Fe-bcc is observed due to the deposition of pure Fe-electrolyte solution. Hence, copper (Cu) concentration is added gradually with Fe-bath solution, then Fe100─XCuX bcc peaks are observed in all remaining three samples through miller indices (200) and (110) planes and suppressed the Fe-bcc peaks completely. The value of the lattice parameter has increased that affects to decrease the lattice strain. Hence, such parameter influences on peaks (FeCu) shift towards lower angle. The grain size shows ascending order by the increment of Cu at%.From M-H loops, it is observed that squareness (MR/MS) and coercivity (Hc) both displays descending order with increment of Cu contents in Fe100─XCuX alloy NWs, having Cu (diamagnetic) with greater atomic radius relative to Fe, that effected to suppress the magnetic moment alignments of Fe. Similarly, iron, which is ferromagnetic material coupling with non-ferromagnetic such as manganese at nanoscale shows interfacial exchange coupling. The Fe-Mn is a biologically (biodegradable) alloying element, as a high ratio of Mn is observed to be not toxic, especially in tiny mesh-like metallic tubular (stent), that increases its effectiveness in the narrow arteries. For such point of view, the last step of this research is directed to synthesize the Fe1─XMnX alloy NWs, by using AC-electrochemical deposition in AAO templates through a similar approach as above. The analysis of X-ray diffraction (XRD) pattern shows that the aluminum peak are observed because of such NWs are characterized with the substrate. The XRD patterns exhibited the FeMn NWs were crystallized into body centered cubic (bcc) structure. Furthermore, the lattice parameter of FeMn NWs was decreased with addition of Mn content. The grain size shows the increasing order (from 38 to 53nm) w.r.t to increase the concentration of Mn in Fe1─XMnX bath solution that effect to decrease the dislocation density and lattice strain of the FeMn alloy NWs. Using four-probe (Hall measurement) technique, it was found that resistivity has been decreased gradually (24 to 75.5 Ω.cm) whereas conductivity declines with an increase in Mn contents by the effect of an increment of the grain size. Hence, behavior of such alloy moves toward the nonmetallic character. The M-H loops demonstrate that shape anisotropy is dominated in Fe1─XMnX alloy NWs. The increase in Mn contents in such alloy, the coercivity and squareness both shows descending order, opposite to that of grain size. Therefore, it has attributed the motion of domain walls due to the decrease the magnetic grain boundaries." xml:lang="en_US