Gilad Orr

Ariel University · Department of Physics

Pulsed Magnetic Field (PMF) is an easy and effective method for changing the properties of various materials. In this work we present the influence of a weak pulsed magnetic field (WPMF) on the recovery and recrystallization processes in 99.99% aluminum. The state of the material before and after processing was determined by the method of Internal...

Calorimetric dosimetry is based on exposing an absorbing body to a radiation field. The energy deposited in the absorber is determined by measuring the absorber temperature rise. We explored the feasibility for obtaining measurable dose rates by using a thin (240 μm ) lead (Pb) plate, a six-fold aluminum/silicon thermopile, and a tungsten W anode...

The complex dielectric permittivity of a sintered ceramic tablet consisting of 70.5% BiFeO 3 , 27.7% Bi 2 Fe 4 O 9 and 1.8% Bi 25 FeO 40 was analyzed as a function of temperature from-120 °C to 230 °C in two separate temperature runs. The results reveal a complicated dielectric response with two temperature activated relaxation processes. The first...

Aluminum single crystals are tested using X-Ray Bragg diffraction, which may have applications in microscopy and electronics fabrication industry. Yet, their efficiency for x-ray beam diffraction depends on the accurate crystal orientation, the microstructure and imperfections. Moreover, the final sample that is formed from the as-grown crystal by...

Exponential growth in solar panel production and energy storage solutions has resulted in pressure on the supply of solar cell materials. Another environmental challenge stems from the fact that panels installed in the 90s and the beginning of the 2000s have reached their end of life and are being discarded in landfills. Hence, in this work, we foc...

The complex dielectric permittivity of a sintered ceramic tablet consisting of 70.5% BiFeO 3 and 27.7% Bi 2 Fe 4 O 9 was analyzed as a function of temperature from − 120°C to 230°C in two separate temperature runs. The results reveal a complicated dielectric response with 2 temperature activated relaxation processes. The first is purely Arrhenius r...

The complex dielectric permittivity of a sintered ceramic tablet consisting of 70.5 \% $BiFeO_{3}$ and 27.7\% $Bi_{2}Fe_{4}O_{9}$ was analyzed as a function of temperature from -120 {\deg}C to 230 {\deg}C. The results reveal a complicated dielectric response with temperature activated relaxation features. They also reveal a ferroelectric phase tran...

The complex dielectric permittivity of a sintered ceramic tablet consisting of 70.5 % BiF eO 3 and 27.7% Bi 2 F e 4 O 9 was analyzed as a function of temperature from-120°C to 230°C. The results reveal a complicated dielectric response with temperature activated relaxation features. They also reveal a ferroelectric phase transition that decayed wit...

Aluminum single crystals are tested using X-Ray Bragg diffraction, which may have applications in microscopy and electronics fabrication industry. Yet, their efficiency for x- ray beam diffraction depends on the accurate crystal orientation, the microstructure and imperfections. Moreover, the final sample that is formed from the as-grown crystal by...

The recent return of the US to the Paris Climate Accord, massive increase in solar panel production and energy storage solutions has resulted in pressure on supply for solar cell materials and recycling of panels installed in the 90's and beginning of the 2000's which have reached their end of life. In this work we focus on recycling silicon wafers...

GaN high electron mobility transistors (HEMT) have gained some foothold in the power electronics industry due to wide frequency bandwidth and power handling. The material offers a wide bandgap and higher critical field strength compared to most wide bandgap semiconductors, resulting in better radiation resistance and theoretically higher speeds as...

Aluminium single crystals may be tested using X-Ray Bragg diffraction in microscopy and electronics fabrication industry. Yet, their efficiency for x-ray beam diffraction depends on the accurate crystal orientation, the microstructure and imperfections. Moreover, the final sample that is formed from the as-grown crystal by cutting, grinding, polish...

The recent return of the US to the Paris climate accord, massive increase in solar panel production and energy storage solutions has resulted in pressure on supply for solar cell material and recycling of panels installed in the 90's and beginning of the 2000's which have reached their end of life. In this work we focus on recycling silicon wafers...

Electropolishing has found wide application as the final surface treatment of metal products in mechanical engineering and instrumentation, medicine and reflective concentrators for PV cells. It was found that electropolishing (EP) not only reduces the surface roughness and changes its appearance, but improves many operational characteristics as we...

Electropolishing has found wide application as the final surface treatment of metal products in mechanical engineering and instrumentation, medicine and reflective concentrators for PV cells. It was found that electropolishing (EP) not only reduces the surface roughness and changes its appearance, but improves many operational characteristics as we...

Ceramic $BiFeO_{3}$ samples were prepared by rapid sintering at $880^OC$. Two compositions were examined. A $56/44\ Bi_{2}O_{3}/Fe_{2}O_{3}\ mole\%$ composition and a $56Bi_{2}O_{3}\cdot44Fe_{2}O_{3}+6.5wt\%\,NaCl$ composition. The samples were heat treated at different times up to $8$ minutes and the phase content was examined as a function of the...

A paper describing an inexpensive open source Bridgman crystal growth system

Single-crystalline silicon Solar cells as a sustainable energy sources, are the most widely used photovoltaics in recent years. The main industrialization process approach of the cells begins with p-type Si wafers followed by junctions and contacts creation. However, photonic energy conversion, both direct and indirect, into electricity suffers fro...

Ceramic BiFeO3 targets were prepared by rapid sintering at 880 degrees Celsius. The samples were heat treated at different times up to 8 minutes and the phase content was examined as a function of the time using XRD measurements and analysis. It was demonstrated that after 3.5 minutes approximately 98.5% of the material transformed to BiFeO3

Ceramic BiFeO3 samples were prepared by rapid sintering at 880 • C. Two compositions were examined. A 56/44 Bi2O3/Fe2O3 mole% composition and a 56Bi2O3 44Fe2O3 + 6.5wt% NaCl composition. The samples were heat treated at different times up to 8 minutes and the phase content was examined as a function of the time using XRD measurements and analysis....

The majority of crystal growth systems require overcoming problems related to process monitoring and continuous electronic control. In order to monitor and control such systems, high quality industrial equipment has to be used, due to its high reliability, requiring minimum long-term maintenance. In particular, reliable temperature controllers, are...

A low cost time domain system for measuring dielectric relaxation in the frequency range of 1 Hz - 1 MHz of solid and molten material at high temperatures is described in detail. A parallel plate electrode sample cell is described that can hold molten material by capillary action. In order to avoid electrical breakdown or a change in electrode dist...

A low-voltage (mV) electronically triggered spot welding system for fabricating fine thermocouples and thin sheets used in high-temperature characterization of materials' properties is suggested. The system is based on the capacitance discharge method with a timed trigger for obtaining reliable and consistent welds. In contrast to existing techniqu...

A modification of the Angsrom's temperature wave method for measuring the thermal properties of materials has been employed for in situ experimental evaluation of thermal diffusivities of high-temperature solutions. High-temperature solutions used for the growth nonlinear optical BBO (BaB2O4) and KTiOPO4 (KTP) crystals have been studied, namely BBO...

Volume phase gratings have been fabricated by controlled generation of periodic striations during the growth of copper doped potassium lithium tantalate niobate crystals. Gratings with periods ranging from below 1 to 5μm were fabricated. It is shown that the fabricated composition grating induces a refractive index grating which is a superposition...

Non-volatile electroholographic diffraction gratings were fabricated by periodically modulating the composition of KLTN crystals. The gratings are manifested as periodic variations of the static dielectric constant which are electrically induced into birefringence gratings.

Off-centered top-seeded solution growth (TSSG) method is demonstrated as an effective and simple way to generate controlled composition modulation in potassium lithium tantalate niobate (KLTN) single crystals. The changes in concentration were measured by differential interference contrast (DIC) microscopy. Large length with periodic modulations ra...