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Pure and 1.0 mol% La 2 O 3 , ZnO, and Cr 2 O 3 -modified 0.675BiFeO 3 -0.325BaTiO 3 (BF-BT) multiferroic ceramics were prepared and comparatively investigated. For pure and La-, Zn-, and Cr-modified BF-BT, the average grain size is 415, 325, 580, and 395 nm, and the maximum dielectric constant temperature is 460°C, 430°C, 465°C, and 445°C, respectively. All additives weaken the ferroelectricity slightly. Znand Cr-modifications dramatically enhance the room-temperature magnetic properties, whereas La-modification has almost no effect on magnetic property. Especially, the Cr-modified BF-BT ceramics show switchable polarization and magnetization of 4.9 lC/cm 2 and 0.27 emu/g at room temperature, the magnetoelectric coupling is confirmed by the magnetizationmagnetic field curves measured on ceramics before and after electric poling. The mechanism responsible for the different effects of additive on microstructures and properties are discussed based on additive-induced point defect and second phase as well as diffusion-induced substitution. These results not only provide a promising room-temperature multiferroic material candidate, but also are helpful to design new multiferroic materials with enhanced properties.

Different from common commercial liquid crystal displays (LCDs), LCDs in military applications have some special requirements including high luminance, wide operating temperature, and night vision compatibility. This paper designs a direct-lit LED backlight for a 5 in×5 in LCDs and puts forward three solutions for heat dissipation. The simulation results show that the solution of 17×17 LED array on common opening FR4 PCB can satisfy the requirement.

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This paper describes a backlight system that can not only reach high luminance but perform a wide color gamut with NVIS compatibility. The backlight consists of red (R), green (G), blue (B), and amber (A) four colors LEDs. During daytimes, RGBA LEDs are simultaneously turned on, providing more luminance and wider color gamut. When working in the night mode, the red LEDs are turned off. The simulation and practical results show that RGBA backlight present the characteristics of high luminance and wide color gamut with compatibility of night vision.