Anomalous coercivity enhancement with temperature and tunable exchange bias in Gd and Ti co-doped BiFeO3_3 multiferroics

We have investigated the effect of temperature on magnetic properties of Bi$_{0.9}$Gd$_{0.1}$Fe$_{1-x}$Ti$_x$O$_3$ (x = 0.00-0.20) multiferroic system. Unexpectedly, the coercive fields ($H_{c}$) of this multiferroic system increased with increasing temperature. The coercive fields and remanent magnetization were higher over a wide range of temperatures in sample x = 0.10 i.e. in sample having composition Bi$_{0.9}$Gd$_{0.1}$Fe$_{0.9}$Ti$_{0.1}$O$_3$ than those of x = 0.00 and 0.20 compositions. Therefore, we have carried out temperature dependent magnetization experiments extensively for sample x = 0.10. The magnetic hysteresis loops at different temperatures exhibit an asymmetric shift towards the magnetic field axes which indicate the presence of exchange bias effect in this material system. The hysteresis loops were also carried out at temperatures 150 K and 250 K by cooling down the sample from 300 K in various cooling magnetic fields ($H_{cool}$). The exchange bias field ($H_{EB}$) values increased with $H_{cool}$ and decreased with temperature. The $H_{EB}$ values were tunable by field cooling at temperatures up to 250 K.Comment: 7 page

Preparation of high crystalline nanoparticles of rare-earth based complex pervoskites and comparison of their structural and magnetic properties with bulk counterparts

A simple route to prepare Gd$_{0.7}$Sr$_{0.3}$MnO$_3$ nanoparticles by ultrasonication of their bulk powder materials is presented in this article. For comparison, Gd$_{0.7}$Sr$_{0.3}$MnO$_3$ nanoparticles are also prepared by ball milling. The prepared samples are characterized by X-ray diffraction (XRD),field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscope (XPS), and Superconducting Quantum Interference Device (SQUID) magnetometer. XRD Rietveld analysis is carried out extensively for the determination of crystallographic parameters and the amount of crystalline and amorphous phases. FESEM images demonstrate the formation of nanoparticles with average particle size in the range of 50-100 nm for both ultrasonication and 4 hours (h) of ball milling. The bulk materials and nanoparticles synthesized by both ultrasonication and 4 h ball milling exhibit a paramagnetic to spin-glass transition. However, nanoparticles synthesized by 8 h and 12 h ball milling do not reveal any phase transition, rather show an upturn of magnetization at low temperature. The degradation of the magnetic properties in ball milled nanoparticles may be associated with amorphization of the nanoparticles due to ball milling particularly for milling time exceeding 8 h. This investigation demonstrates the potential of ultrasonication as a simple route to prepare high crystalline rare-earth based manganite nanoparticles with improved control compared to the traditional ball milling technique.Comment: 9 pages, 6 figure

Efek Nefroprotektor Ekstrak Daun Kemangi (Ocimum sanctum) Terhadap Kerusakan Sel Ginjal Mencit (Mus musculus) Yang Diinduksi Parasetamol

Background: Today, consuming paracetamol as an analgesic antipyretic drugs has increased. Paracetamol which used in inappropriate dose has bad effect to our body, such as nefrotoxic. Basil leaf extract has antioxidant as a protection of free radicals and reducing NAPQI which produced by paracetamol. The objectives of this research are to know the nefroprotector effect and this research will shown the multilevel dose of basil leaf extract as a nefroprotector in the renal cell damage induced by parasetamol. Methods: This was experimental laboratory with the post test only controlled group design. Sample group consisted of male mice Swiss Webster, 2-3 month, + 20 g. Samples divided into 4 groups, each group has seven mice. Mice for control group (K) and the first treatment group (P1) were given aquades for 14 days. The second treatment group (P2) will be given basil leaf extract dose I for 14 days. The third treatment group (P3) will be given basil leaf extract dose II for 14 days. Paracetamol will be given to P1, P2, and P3, with dose 0,1 ml/20 gr weight of mice on the day 12, 13, and 14. Finally on day 15 th , mice are sacrificed with neck dislocation then the renal of mice was made preparations with paraffin blocks methods and Hematoxillin Eosin staining. Renal cell damage observed and counted a mount of scored on renal histological karyopyknosis, karyorrhexis, and karyolysis. Data are analized by One-Way ANOVA test (α= 0,05) and continued by Post Hoc Multiple Comparisons test (LSD) (α = 0,05). Results: Result of One-Way ANOVA shown that there was a significant of degree between 4 groups. Result of LSD method there was a significant of degree between K-P1, K-P2, P1-P2, and P1-P3 groups; and also it wasn’t a significant of degree between K-P3 and P2-P3. Conclusions: The basil leaf extracts was able to decrease the renal cell damaging of mice and the increase of basil leaf extracts dose followed by the increase of protection effect to the renal cell damaging of mice which is induced by paracetamol

Lorentz TEM imaging of stripe structures embedded in a soft magnetic matrix

N\'eel walls in soft magnetic NiFe/NiFeGa hybrid stripe structures surrounded by a NiFe film are investigated by high resolution Lorentz transmission electron microscopic imaging. An anti-parallel orientation of magnetization in 1000 nm wide neighboring unirradiated-irradiated stripes is observed by forming high angle domain walls during magnetization reversal. Upon downscaling the stripe structure size from 1000 nm to 200 nm a transition from a discrete domain pattern to an effective magnetic medium is observed for external magnetic field reversal. This transition is associated with vanishing ability of hosting high angle domain walls between adjacent stripes. The investigation also demonstrated the potentiality of Lorentz microscopy to image periodic stripe structures well under micron length-scale.Comment: 7 pages, 6 figure

Pemanfaatan Energi Matahari Sebagai Backup Energi Listrik Pada Beban Rumah Tangga 450 VA

This time enlarge of electric power is needed but supply of electric power is too limit. To solve this problem so are needed alternatives energy. Like a solar energy to change the unrenewable energy. To use the solar energy are needed solar cell to change from solar energy to electric powers. The electric powers are produced by a solar cell with 50 WP until ± 19,1 volt and the max current that flow of its are about 1,67 ampere. After that, the electrical powers save in battery and the Voltage output of this battery are raised by boost converter until 175 volt as Voltage input of the inverter. The inverter changes from DC voltage of this to AC voltage 125 volt and this electric power ready to supply the household device. Keyword: solar cell, boost converter, inverter

Size dependent magnetic and electrical properties of Ba-doped nanocrystalline BiFeO3_3

Improvement in magnetic and electrical properties of multiferroic BiFeO$_3$ in conjunction with their dependence on particle size is crucial due to its potential applications in multifunctional miniaturized devices. In this investigation, we report a study on particle size dependent structural, magnetic and electrical properties of sol-gel derived Bi$_{0.9}$Ba$_{0.1}$FeO$_3$ nanoparticles of different sizes ranging from $\sim$ 12 to 49 nm. The substitution of Bi by Ba significantly suppresses oxygen vacancies, reduces leakage current density and Fe$^{2+}$ state. An improvement in both magnetic and electrical properties is observed for 10 % Ba-doped BiFeO$_3$ nanoparticles compared to its undoped counterpart. The saturation magnetization of Bi$_{0.9}$Ba$_{0.1}$FeO$_3$ nanoparticles increase with reducing particle size in contrast with a decreasing trend of ferroelectric polarization. Moreover, a first order metamagnetic transition is noticed for $\sim$ 49 nm Bi$_{0.9}$Ba$_{0.1}$FeO$_3$ nanoparticles which disappeared with decreasing particle size. The observed strong size dependent multiferroic properties are attributed to the complex interaction between vacancy induced crystallographic defects, multiple valence states of Fe, uncompensated surface spins, crystallographic distortion and suppression of spiral spin cycloid of BiFeO$_3$.Comment:

Application Receipt Claims on PT. Blue Bird Group Using Microsoft Visual Basic 6.0

Invoice receipt is a letter received by the suppliers of the company PT. Blue Bird, which is temporary and used to collect payment on PT. Blue Bird. This process is usually done by employees with the manual way, so the possibility of human error in the data storage process is very large. This was due to the lack of applications and places to accommodate a portion of the claim data into one place. For that writers create applications that can assist companies in managing performance data and storing bills into a database, so that data security can be maintained adequately