We report the electrical detection of magnetization dynamics in an Al/AlOx/Ni80Fe20/Cu tunnel junction, where a Ni80Fe20 ferromagnetic layer is brought into precession under ferromagnetic resonance conditions. The dc voltage generated across the junction by the precessing ferromagnet is enhanced about an order of magnitude compared to the voltage signal observed when the contacts in this type of multilayered structure are Ohmic. We discuss the relation of this phenomenon to magnetic spin pumping and speculate on other possible underlying mechanisms responsible for the enhanced electrical signal.

Microwave-assisted magnetization switching was investigated using Fe30Co70∕AlOx∕Ni80Fe20 magnetic tunnel junctions incorporated with a coplanar waveguide. Coercivity field of Ni80Fe20 layer was dramatically reduced in a small amplitude microwave. The authors eliminated the thermal effect in coercivity reduction by comparing two types of measurements which are with and without spin precession in the presence of microwave. It was found that the coercivity reduction depends on both frequency and power of the microwave. The numerical simulation based on Landau-Lifshitz-Gilbert equation reproduced the trend of the experimental data. The results indicate that microwave can be an efficient means to switch the magnetization of a thin film.

A compact circularly polarized slot antenna is proposed in this paper, which has a much wider operation bandwidth compared to the antennas with similar sizes. This antenna is designed for universal ultrahigh frequency (UHF) radio frequency identification (RFID) reader applications. The antenna is CPW-fed by an L-shaped feeding line. To achieve good impedance matching and broadband CP operation, two L-shaped strip lines are inserted into the circular slot in the ground plane. The measured 10-dB return loss bandwidth is 380 MHz (618-998 MHz, 47.0% centered at 808 MHz). The measured 3-dB axial ratio bandwidth is about 332 MHz (791-1123 MHz, 34.7% centered at 957MHz). The overall size of the antenna is 120 × 120 × 0.8 mm 3 .

Ab iomimetic catalyst ……f CO 2 photoreduction was developed through self-assembling porphyrins a hydrogen-bonded organic framework, as reported by Tian-Fu Liu, Rong Cao,a nd coworkers in their Research Article (e202203955). Thec ombination of photosensitizers and redox centers in the structure not only allows for adequate photon input and efficient utilization of the photogenerated charge,b ut also changes the microenvironment surrounding the active sites.

technology because of its higher brightness, lower power consumption, and faster response than OLED and LCD technologies. [1-5] They are expected to be suited for many applications in the brightnesssensitive or power-sensitive environments such as wearable devices, optogenetics, outdoor displays, and AR/VR. [6-13] Despite these attractive advantages, fabricating high-resolution micro-LED displays is proven to be very challenging because accurately assembling millions of micro-LEDs onto a driving circuit requires complicated transfer and bonding process. [3,14] A scalable active-driven micro-LED display device is primarily composed of two major parts: a micro-LED array, and a driver backplane. [14-20] In order to generate any display pattern, the micro-LED array must be electrically connected to the pads on the driver backplane. This is most commonly achieved by flip-chip bonding technologies such as bump bonding and anisotropic conductive film (ACF) bonding, [13] whereas in some cases it can be done using via filling or metal wiring technology. [3,4,21] The latter technology is not preferred, because for high-resolution display, both metal wires and vias occupy extra space. In the course of bonding, the small chip size may incur serious registration/alignment errors, resulting in forming display defects. Therefore, the fabrication of a micro-LED display device involves two challenging processes: i) assembling millions of micro-LED chips in a fast, accurate, and low-cost manner, and ii) reliably bonding the micro-LEDs onto the driver circuit with minimized displacement. Micro-LED arrays can be made in a monolithic manner, without using tedious pick-and-place technology. [12] In a monolithic approach, an array of micropixels is formed simultaneously on the same native substrate using only a lithography process, and all these pixels on the same substrate are then integrated onto a driver backplane via one-time flip-chip bonding. Optionally, the sapphire can be taken off by laser liftoff (LLO), [21,22] in order to suppress the optical crosstalk and beam divergence induced by the thick substrate. [23,24] Flip-chip bonding is a proven technology which is fast and compatible with wafer-level bonding. Furthermore, it can improve the light-emitting efficiency because of less light absorption caused The development of micro-sized light emitting diode (LED) displays has driven the research of micro-LED mass-transfer technology. To date, various transfer technologies are proposed, but ample room for improvements in the transfer yield and transfer accuracy still remains. Furthermore, whether these techniques are suited for the subsequent bonding process is not well investigated, which is essential for achieving a good electric connection between micro-LEDs and driver electronics. Here a systematical solution, termed as "tape-assisted laser transfer," which is not only suited for high-yield micro-LED transfer but also well compatible with subsequent bonding process, is developed. Using a low-cost adhesive tape as the support s...

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This article initially proposes a directly‐fed circular patch antenna with L‐shaped ground plane for Radio Frequency Identification (RFID) applications in the 900 MHz (902−928 MHz) ultrahigh frequency (UHF) band. To achieve circularly polarized (CP) radiation, two arc‐shaped notches are loaded into the main patch. To enhance the CP bandwidth so that the proposed antenna can also cover the UHF RFID band for Europe (866−869 MHz), a parasitic element is printed besides the main patch. Experimental measurements show that the 10‐dB return loss bandwidth of the proposed antenna was 30.95% (833−1138 MHz) and its corresponding 3‐dB axial ratio bandwidth was 8.95% (865−946 MHz). Good gain and radiation efficiency of more than 7 dBic and 90%, respectively, were also exhibited across the two desired UHF RFID bands. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:681–687, 2015.