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<jats:p>Metal/semiconductor memristive heterostructures have potential applications in nonvolatile memory and computing devices. To enhance the performance of the memristive devices, it requires a comprehensive engineering to the metal/semiconductor interfaces. Here in this paper, we discuss the effects of oxygen vacancies and temperature on the memristive behaviors of perovskite-oxide Schottky junctions, each consisting of SrRuO<jats:sub>3</jats:sub> thin films epitaxially grown on Nb:SrTiO<jats:sub>3</jats:sub> substrates. The oxygen partial pressure and laser fluence are controlled during the film growth to tune the oxygen defects in SrRuO<jats:sub>3</jats:sub> films, and the Schottky barrier height can be controlled by both the temperature and oxygen vacancies. The resistive switching measurements demonstrate that the largest resistance switching ratio can be obtained by controlling oxygen vacancy concentration at lower temperature. It suggests that reducing Schottky barrier height can enhance the resistive switching performance of the SrRuO<jats:sub>3</jats:sub>/Nb:SrTiO<jats:sub>3</jats:sub> heterostructures. This work can conduce to the development of high-performance metal-oxide/semiconductor memristive devices.</jats:p>

<jats:p>We report the detailed physical properties of quaternary compound Ba<jats:sub>2</jats:sub>BiFeS<jats:sub>5</jats:sub> with the key structural ingredient of isolated FeS<jats:sub>4</jats:sub> tetrahedra. Magnetization and heat capacity measurements clearly indicate that Ba<jats:sub>2</jats:sub>BiFeS<jats:sub>5</jats:sub> has a paramagnetic to antiferromagnetic transition at about 30 K. The calculated magnetic entropy above ordering temperature is much smaller than theoretical value for high-spin Fe<jats:sup>3+</jats:sup> ion with <jats:italic>S</jats:italic> = 5/2, implying the possible short-range antiferromagnetic fluctuation in Ba<jats:sub>2</jats:sub>BiFeS<jats:sub>5</jats:sub>.</jats:p>

<jats:p>In this paper, the giant magnetoresistance (GMR) multilayer sensor is fabricated with a Wheatstone bridge, and it exhibits excellent performance with a sensitivity of 2.8349 mV/(V/Oe) (<jats:inline-formula> <jats:tex-math> <?CDATA $1\,\mathrm{Oe}=79.5775\,{\rm{A}}\cdot {{\rm{m}}}^{-1}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>1</mml:mn> <mml:mspace width="0.25em" /> <mml:mi>Oe</mml:mi> <mml:mo>=</mml:mo> <mml:mn>79.5775</mml:mn> <mml:mspace width="0.25em" /> <mml:mi mathvariant="normal">A</mml:mi> <mml:mo>·</mml:mo> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">m</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_087501_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>) and a saturation field of 26 Oe along the sensitive axis. The GMR sensor is also characterized in a high magnetic field. The sensitivity decreases from 2.8349 mV/(V/Oe) at an angle of 0° to 0.0175 mV/(V/Oe) at an angle of 90°. Then, the sensor is placed in a series of rotating magnetic fields. We propose a model to express the output characteristics of the GMR multilayer sensor. The transfer curves of the sensor can be shown as two exactly symmetrical circles with an increasing radius when the magnetic field increases. The experimental results are consistent with the simulation results of the model. The advantage of this model is that it is simpler and more intuitive.</jats:p>

<jats:p>Amorphous (Fe<jats:sub>40</jats:sub>Ni<jats:sub>40</jats:sub>B<jats:sub>19</jats:sub>Cu<jats:sub>1</jats:sub>)<jats:sub>100−<jats:italic>x</jats:italic> </jats:sub>Nb<jats:sub> <jats:italic>x</jats:italic> </jats:sub> (<jats:italic>x</jats:italic> = 1, 3, 5, 7) ribbons are prepared by using the melt-spinning method. We find that the glass forming ability (GFA) of the as-melt spun ribbons is significantly improved by adding Nb element. In addition, the thermal stability evaluated in steps of <jats:inline-formula> <jats:tex-math> <?CDATA ${\rm{\Delta }}T={T}_{x2}-{T}_{x1}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi mathvariant="normal">Δ</mml:mi> <mml:mi>T</mml:mi> <mml:mo>=</mml:mo> <mml:msub> <mml:mrow> <mml:mi>T</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>x</mml:mi> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:mo>−</mml:mo> <mml:msub> <mml:mrow> <mml:mi>T</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>x</mml:mi> <mml:mn>1</mml:mn> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_087502_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> effectively increases from 16 K to 75 K with Nb content increasing. The as-melt spun (Fe<jats:sub>40</jats:sub>Ni<jats:sub>40</jats:sub>B<jats:sub>19</jats:sub>Cu<jats:sub>1</jats:sub>)<jats:sub>97</jats:sub>Nb<jats:sub>3</jats:sub> ribbon exhibits a lowest coercivity of 2 A/m and relatively large saturation magnetization of <jats:inline-formula> <jats:tex-math> <?CDATA $103.7\,{\rm{A}}\cdot {{\rm{m}}}^{2}/\mathrm{kg}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>103.7</mml:mn> <mml:mspace width="0.25em" /> <mml:mi mathvariant="normal">A</mml:mi> <mml:mo>·</mml:mo> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">m</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mrow> <mml:mo stretchy="false">/</mml:mo> </mml:mrow> <mml:mi>kg</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_087502_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> and thus it can be further treated by being annealed at 809 K. The crystallization behavior is confirmed to be determined by two individual crystallization processes corresponding to the precipitation of (Fe,Ni)<jats:sub>23</jats:sub>B<jats:sub>6</jats:sub> phase and <jats:italic>γ</jats:italic>-(Fe,Ni) phase. With increasing annealing time, the single (Fe,Ni)<jats:sub>23</jats:sub>B<jats:sub>6</jats:sub> phase can be transformed into a mixture of (Fe,Ni)<jats:sub>23</jats:sub>B<jats:sub>6</jats:sub> and <jats:italic>γ</jats:italic>-(Fe,Ni) phase, and the grain size of <jats:italic>γ</jats:italic>-(Fe, Ni) phase increases from 5 nm to 80 nm while the grain size of (Fe,Ni)<jats:sub>23</jats:sub>B<jats:sub>6</jats:sub> remains almost unchanged. Finally, we find that the grain growth in each of (Fe,Ni)<jats:sub>23</jats:sub>B<jats:sub>6</jats:sub> and <jats:italic>γ</jats:italic>-(Fe, Ni) deteriorates the overall magnetic properties.</jats:p>

<jats:p>Magnetic skyrmions have interesting properties, including their small size, topological stability, and extremely low threshold current for current-driven motion. Therefore, they are regarded as promising candidates for next-generation magnetic memory devices. Lorentz transmission electron microscopy (TEM) has an ultrahigh magnetic domain resolution (∼2 nm), it is thus an ideal method for direct real-space imaging of fine magnetic configurations of ultra-small skyrmions. In this paper, we describe the basic principles of Lorentz-TEM and off-axis electron holography and review recent experimental developments in magnetic skyrmion imaging using these two methods.</jats:p>

<jats:p>Pr<jats:sup>3+</jats:sup>-doped calcium niobium gallium garnet (Pr:CNGG) single crystals with different Pr<jats:sup>3+</jats:sup>concentrations are successfully grown by the micro-pulling-down (<jats:italic>μ</jats:italic>-PD) method. The crystal structure, room-temperature absorption spectra, and fluorescence spectra of Pr:CNGG crystals are measured and discussed. The fluorescence results indicate their large dependence on the doping concentration. The fluorescence lifetime of the <jats:inline-formula> <jats:tex-math> <?CDATA ${}^{1}{\rm{D}}_{2}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mmultiscripts> <mml:mrow> <mml:mi mathvariant="normal">D</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> <mml:none /> <mml:mprescripts /> <mml:none /> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> </mml:mmultiscripts> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_087801_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> energy level is also determined. The results indicate that Pr:CNGG crystal could be a potential solid-state laser gain medium.</jats:p>

<jats:p>The epitaxial growth of novel GaN-based light-emitting diode (LED) on Si (100) substrate has proved challenging. Here in this work, we investigate a monolithic phosphor-free semi-polar InGaN/GaN near white light-emitting diode, which is formed on a micro-striped Si (100) substrate by metal organic chemical vapor deposition. By controlling the size of micro-stripe, InGaN/GaN multiple quantum wells (MQWs) with different well widths are grown on semi-polar (<jats:inline-formula> <jats:tex-math> <?CDATA $1\bar{1}01$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>1</mml:mn> <mml:mover accent="true"> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>¯</mml:mo> </mml:mrow> </mml:mover> <mml:mn>01</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_087802_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula>) planes. Besides, indium-rich quantum dots are observed in InGaN wells by transmission electron microscopy, which is caused by indium phase separation. Due to the different widths of MQWs and indium phase separation, the indium content changes from the center to the side of the micro-stripe. Various indium content provides the wideband emission. This unique property allows the semipolar InGaN/GaN MQWs to emit wideband light, leading to the near white light emission.</jats:p>

<jats:p>Multiphoton excitations and nonlinear optical properties of exciton states in GaAs/Al<jats:sub> <jats:italic>x</jats:italic> </jats:sub>Ga<jats:sub>1−<jats:italic>x</jats:italic> </jats:sub>As coupled quantum well structure have been theoretically investigated under the influence of a time-varying high-intensity terahertz (THz) laser field. Non-perturbative Floquet theory is employed to solve the time-dependent equation of motion for the laser-driven excitonic quantum well system. The response to the field parameters, such as intensity and frequency of the laser electric field on the state populations, can be used in various optical semiconductor device applications, such as photodetectors, sensors, all-optical switches, and terahertz emitters.</jats:p>

<jats:p>In this work, we designed the elliptical thermal cloak based on the transformation thermotics. The local entropy generation rate distribution and entransy dissipation rate distribution were obtained, and the total entropy generation and entransy dissipation of different types of elliptical cloaks were evaluated. We used entropy generation approach and entransy dissipation approach to evaluate the performance of the thermal cloak, and heat dissipation analysis was carried out for models with different parameters. Finally, the optimized elliptical thermal cloak with minimum entropy generation and minimum entransy dissipation is found, and some suggestions on optimizing the structure of elliptical thermal cloak were given.</jats:p>

<jats:p>The thin film properties of organic semiconductors are very important to the device performance. Herein, non-planar vanadyl phthalocyanine (VOPc) thin films grown on rigid substrates of indium tin oxide, silicon dioxide, and flexible substrate of kapton by organic molecular beam deposition under vacuum conditions are systematically studied via atomic force microscopy and x-ray diffraction. The results clearly reveal that the morphology and grain size are strongly dependent on the substrate temperature during the process of film deposition. Meanwhile, the VOPc films with the structure of phase I or phase II can be modulated via in situ annealing and post-annealing temperature. Furthermore, the crystalline structure and molecular orientation of vapor-deposited VOPc can be controlled using molecular template layer 3, 4, 9, 10-perylene-tetracarboxylic dianhydride (PTCDA), the VOPc film of which exhibits the phase I structure. The deep understanding of growth mechanism of non-planar VOPc film provides valuable information for controlling structure-property relationship and accelerates the application in electronic and optoelectronic devices.</jats:p>