（Na1／2Bi1／2）TiO3—SrTiO3无铅压电陶瓷的介电,压电性能

研究了（Ｎａ１／２Ｂｉ１／２）ＴｉＯ３－ＳｒＴｉＯ３二元系无铅压电陶瓷的介电、压电性性。Ｓｒ＾２＋的引入对ＮＢＴ材料的常温介电系数、铁电相与反铁电相转变温度ＴＦＡ（１８０℃）以及居里温度ＴＣ（３００℃）的影响都不大,但却较大幅度地降低了ＮＢＴ材料的高顽场,从而使极化相对容易。（Ｎａ１／２Ｂｉ１／２）ＴｉＯ－ＳｒＴｉＯ３二元系的压电性能参数ｄ３３和ｋｔ分别达到１００ｐＣ／Ｎ和０．４５。     

一种铌镁酸铅—钛酸铅晶体的铁电相变研究

研究了Ｐｂ（Ｍｇ１／３Ｎｂ２／３）Ｏ３－ＰｂＴｉＯ３晶体的介电、热电和压电性质，温度测量范围为７０Ｋ～６００Ｋ。发现它不仅在４７４Ｋ附近有一铁电－顺电相变，而且在１８０Ｋ附近还存在一个铁电－铁电相变。在相变温度区域里，介电、热电和压电都有明显的热滞效应，具有一级相变特性。     

掺杂及烧结温度对Pb(Y1/2Nb1/2)O3-PbTiO3-PbZrO3性能的影响

为了改进０．０２Ｐｂ（Ｙ１／２Ｎｂ１／２ ）Ｏ３－ｙＰｂＴｉＯ３－（１－ ０．０２－ ｙ）ＰｂＺｒＯ３ 系压电陶瓷的电学性能和力学性能,作者研究了多种常用添加物对０．０２Ｐｂ （Ｙ１／２Ｎｂ１／２ ）Ｏ３ －ｙＰｂＴｉＯ３ －（１－ ｙ－ ０．０２）ＰｂＺｒＯ３ 三元系压电陶瓷性能的作用, 探讨了不同烧结温度对材料性能的影响。实验结果表明, Ｓｒ２＋ 和Ｂａ２＋ 作为同价取代元素能够提高０．０２Ｐｂ（Ｙ１／２Ｎｂ１／２ ） Ｏ３ －ｙＰｂＴｉＯ３ －（１－ ０．０２－ ｙ） ＰｂＺｒＯ３ 系材料的机电耦合系数（ｋｐ、ｋ３３ 、ｋｔ）、介电常数和压电系数, 降低机械品质因数Ｑｍ ; Ｌｉ＋ 、Ｃｒ３＋ 、Ｍｎ２＋ 、Ｎｉ３＋ 、Ｆｅ３＋ 等金属离子加入０．０２Ｐｂ （Ｙ１／２Ｎｂ１／２） Ｏ３－ｙＰｂＴｉＯ３－（１－ ０．０２－ ｙ） ＰｂＺｒＯ３ 会提高材料的机械品质因数, 同时也会损害介电、压电性能, 降低弹性柔顺系数, 体现了硬性添加物的一般特性; 退火对０．０２Ｐｂ （Ｙ１／２Ｎｂ１／２） Ｏ３ －ｙＰｂＴｉＯ３－ （１－ ０．０２－ ｙ） ＰｂＺｒＯ３ 压电材料性能有促进作用。     

掺杂及烧结温度对Pb(Y_(1/2)Nb_(1/2))O_3-PbTiO_3-PbZrO_3性能的影响

为了改进０．０２Ｐｂ（Ｙ１／２Ｎｂ１／２ ）Ｏ３－ｙＰｂＴｉＯ３－（１－ ０．０２－ ｙ）ＰｂＺｒＯ３ 系压电陶瓷的电学性能和力学性能,作者研究了多种常用添加物对０．０２Ｐｂ （Ｙ１／２Ｎｂ１／２ ）Ｏ３ －ｙＰｂＴｉＯ３ －（１－ ｙ－ ０．０２）ＰｂＺｒＯ３ 三元系压电陶瓷性能的作用, 探讨了不同烧结温度对材料性能的影响。实验结果表明, Ｓｒ２＋ 和Ｂａ２＋ 作为同价取代元素能够提高０．０２Ｐｂ（Ｙ１／２Ｎｂ１／２ ） Ｏ３ －ｙＰｂＴｉＯ３ －（１－ ０．０２－ ｙ） ＰｂＺｒＯ３ 系材料的机电耦合系数（ｋｐ、ｋ３３ 、ｋｔ）、介电常数和压电系数, 降低机械品质因数Ｑｍ ; Ｌｉ＋ 、Ｃｒ３＋ 、Ｍｎ２＋ 、Ｎｉ３＋ 、Ｆｅ３＋ 等金属离子加入０．０２Ｐｂ （Ｙ１／２Ｎｂ１／２） Ｏ３－ｙＰｂＴｉＯ３－（１－ ０．０２－ ｙ） ＰｂＺｒＯ３ 会提高材料的机械品质因数, 同时也会损害介电、压电性能, 降低弹性柔顺系数, 体现了硬性添加物的一般特性; 退火对０．０２Ｐｂ （Ｙ１／２Ｎｂ１／２） Ｏ３ －ｙＰｂＴｉＯ３－ （１－ ０．０２－ ｙ） ＰｂＺｒＯ３ 压电材料性能有促进作用。     

PZN—PNN——PZT体系压电陶瓷

对ＰＺＮ－ＰＮＮ－ＰＺＴ四元素统压电陶瓷组成与性能的关系进行了研究。通过Ｃａ、Ｓｒ、Ｂａ等元素对部分Ｐｂ的转换以及用Ｌｉ２ＣＯ３、Ｓｂ２Ｏ３等适当掺杂改性，可获得相对介电常数ε３３／ε０约７０００，压电应变常数ｄ３３约８００ｐＣ／Ｎ，机电耦合系数ｋｐ约０．６５的一系列高性能压电陶瓷，是用于制作压电超声马达及各类高档压电电声器件的良好材料。     

掺Pb[(Y1/2Nb1/2)0.06(Zr1/2Ti1/2)0.94]O3铁电陶瓷的性能

研究了ＭｎＯ２、ＭｇＯ 掺杂的０．０６Ｐｂ（Ｙ１／２Ｎｂ１／２）Ｏ３－０．９４Ｐｂ（Ｚｒ１／２Ｔｉ１／２）Ｏ３ 三元系压电陶瓷。通过测量得出了不同组分时的压电常数、机电耦合系数、极化前后的介电常数以及弹性柔顺系数;获得掺杂物与这些性能之间的关系;对实验现象进行了简单的讨论,得出一些有益的结论     

PVDF/PMN-PZT复合驻极体薄膜及其特性

采用流延法制备了ＰＶＤＦ／ＰＭＮ－ＰＺＴ两相３－０型柔性复合驻极体薄膜，研究了其形成与结构，探讨了电晕注极技术，以及复合驻极体的介电、压电与电荷存贮效应与机理。该柔性复合驻极体薄膜厚５０～１５０μｍ，压电应变常数ｄ３３为３５～４５ｐＣ／Ｎ，相对介电系数εｒ为６０～８０，寿命≥５５年。     

PBSZT弛豫铁电陶瓷偏压压电效应的研究

研究了镧和铋掺杂的锆钛酸铅钡锶（ＰＢＳＺＴ）弛豫铁电陶瓷在不同直流偏压及温度下的介电常数ε３３、平面机电耦合系数ｋｐ 和等效横向压电常数ｄ３１。实验表明,ＰＢＳＺＴ弛豫铁电陶瓷的ｄ３１值可由直流偏压控制且温度系数远小于ＰＭＮ－ＰＴ系陶瓷。室温下镧和铋掺杂的ＰＢＳＺＴ陶瓷在１０ ｋＶ／ｃｍ 的偏压下｜ｄ３１｜分别为２１０ ｐＣ／Ｎ和２２０ ｐＣ／Ｎ。     

xPb（Y1／2Nb1／2）O3—yPbTiO3—zPbZrO3压电陶瓷的研究

对ｘＰｂ（Ｙ１／２Ｎｂ１／２）Ｏ３－ｙＰｂＴｉＯ３－ｚＰｂＺｒＯ３三元系陶瓷材料进行了研究,对其压电与介电性能进行了测量,发现该三元系材料在ｘ＝０．２～０．５,ｙ＝０．４３～０．４６,ｚ＝０．５５～０．５８,具有优异的压电性能,在该范围内,陶瓷材料的居里点在４００℃以上,实验表明该材料是一种具有良好应用前景的压电材料。     

（Pb,La）TiO3铁电薄膜的制备及热释电性能研究

讨论了ＰＬＴ１５铁电薄膜的溶胶－凝胶制备技术,及ＰＬＴ薄膜的结构和电性能研究。结果表明,在Ｓｉ基片上成功地生长出钙钛矿型结构多晶铁电薄膜,在（１１１）Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ上外延生长出（１１１）ＰＬＴ１５铁电薄膜。溶胶－凝胶制备的ＰＬＴ１５铁电薄膜具有优良的热释电性能,其热释电系数ｐ为５．２５×１０－８Ｃｃｍ－２Ｋ－１,电压响应率优值ＦＶ达到０．７８×１０－１０Ｃｃｍ／Ｊ,探测率优值Ｆｍ为１．１３×１０－８Ｃｃｍ／Ｊ,适于制备热释电红外探测器     

Quantum codes [[6, 2, 3]]/sub p/ and [[7, 3, 3]]/sub p/ (p /spl ges/ 3) exist

We prove that nonbinary quantum stabilizer codes with parameters [[n, k, d]]/sub p/ = [[6, 2, 3]]/sub p/ and [[7, 3, 3]]/sub p/ exist for all odd primes p by using graph machinery, given by Schlingemann and Werner(see Phys. Rev. A, vol.65, no.012308, 2001), with a little number theory and combinatorics.     

Dielectric properties of single crystals of Al2O3, LaAlO3, NdGaO3, SrTiO3, and MgOat cryogenic temperatures

A dielectric resonator technique has been used for measurements of the permittivity and dielectric loss tangent of single-crystal dielectric substrates in the temperature range 20-300 K at microwave frequencies. Application of superconducting films made it possible to determine dielectric loss tangents of about 5×10^-7 at 20 K. Two permittivity tensor components for uniaxially anisotropic samples were measured. Generally, single-crystal samples made of the same material by different manufacturers or by different processes save significantly different losses, although they have essentially the same permittivities. The permittivity of one crystalline ferroelectric substrate, SrTiO₃, strongly depends on temperature. This temperature dependence can affect the performance of ferroelectric thin-film microwave devices, such as electronically tunable phase shifters, mixers, delay lines and filters     

Laser action from Ho3+, Er3+, and Tm3+in YAlO3

Laser action has been observed for the following rare-earth ions in YAlO3:Ho³⁺(sensitized with Er³⁺and Tm³⁺), Er³⁺, and Tm³⁺(sensitized with Er³⁺) at wavelengths of 2.123, 0.851, and 1.861 μm, respectively. Measurements of spectroscopic properties, fluorescence kinetics, and laser performance of these ions in YAlO3are reported.     

Some optical properties of KTP, LiIO3, and LiNbO3

Measurements of the absorption coefficient for KTP, LiIO₃ , and LiNbO₃ are discussed. The variation of the refractive index with temperature has been measured for KTP and LiIO₃. It is necessary to know both the absorption coefficient β and the variation in the indexes of refraction with temperature change dn/dT to determine the average power limit of a nonlinear interaction. With the dn/dT information, it is also possible to estimate the temperature half width of any nonlinear interaction by calculating the variation of the phase-matching condition with temperature     

Infrared cross-section measurements for crystals doped withEr3+, Tm3+, and Ho3+

The absorption and emission cross sections of the transition between the ground spin-orbit multiplet and the lowest excited multiplet were measured for Er³⁺, Tm³⁺, and Ho³⁺ ions in a variety of crystalline hosts. The materials that were investigated include LiYF₄, BaY₂F₈, Y ₃Al₅O₁₂, LaF₃, KCaF₃ , YAlO₃, and La₂Be₂O₅. The absolute magnitudes of the emission cross sections were determined from the absorption spectra, with the aid of the principle of reciprocity. The calculated radiative emission lifetimes derived from these measured cross sections agree well with the measured emission decay times for most materials. The potential use of these rare-earth-doped materials in pulsed laser applications requires that the ground state exhibit adequate splitting to minimize the detrimental effects of the ground state thermal population, and also that the emission cross section be sufficiently large to permit efficient extraction energy. The systems based on Ho³⁺ in the eightfold coordinated sites of LiYF₄, BaY₂F₈, and Y₃Al₅O₁₂ appear to be the most promising     

Infrared temperature tunability in GaSe, HgS, and Tl3AsSe3nonlinear devices

Temperature coefficients of refractive indexesdn/dtdetermine temperature stability and temperature tuning in nonlinear optical laser devices. These coefficients for three infrared crystals HgS, GaSe, and Tl3AsSe3are analyzed for the first time to find refractive indexes at different temperatures to predict therefrom the tuning curves for some three-wave parametric interactions.     

Piezoelectric Study of 0.65Pb(Mg1/3,Nb2/3)O3-0.35PTO3 Nanopoder Ceramics

The piezoelectric properties of relaxor ferroelectric 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 ceramic prepared by a sol-gel combustion method have been investigated as function of sintering temperature. The results show that its phase structure is near the morphoteropic phase boundary (MPB), and outstanding electrical properties are obtained with this composition. The highest piezoelectric coefficients were observed for the samples sintered at temperature of 1200oC. In comparison with pure PMN ((1-x)Pb(Mg1/3Nb2/3)O3(x)PbTiO3), the substitution of 35% PT results in the decrease of sintered temperature and improved the relaxation behavior.     

Magnetic properties of Co- and Mn-implanted BaTiO3, SrTiO3 and KTaO3

Implantation of Co or Mn into single-crystal BaTiO₃(K), SrTiO₃ or KTaO₃(Ca), followed by annealing at 700 °C, produced ferromagnetic behavior over a broad range of transition metal concentrations. For BaTiO₃, both Co and Mn implantation produced magnetic ordering temperatures near 300 K with coercivities 70 Oe. The M–T plots showed either a near-linear decrease of magnetization with increasing temperature for Co and a non-Brillouin shaped curve for Mn. No secondary phases were detected by high-resolution X-ray diffraction. The same basic trends were observed for both SrTiO₃ and KTaO₃, with the exception that at high Mn concentrations (5 at.%) the SrTiO₃ was no longer ferromagnetic. Our results are consistent with recent reports of room temperature ferromagnetism in other perovskite systems (e.g. LaBaMnO₃) and theoretical predictions for transition metal doping of BaTiO₃ [Nakayama et al., Jap. J. Appl. Phys. 40 (2001) L1355].     

ITO-free,efficient, and inverted phosphorescent organic light-emitting diodes using a WO3/Ag/WO3 multilayer electrode

We present an indium tin oxide (ITO)-free, bottom-emission inverted phosphorescent organic light-emitting diode (PHOLED) with a maximum luminance of 280,000 cd/m² at 8 V, total maximum current efficiency of 81.4 cd/A, and external quantum efficiency of 22.4%. The inverted OLED structure is composed of glass/WO₃ (30 nm)/Ag (15 nm)/WO₃ (5 nm)/BPhen:15wt% CS₂CO₃ (5 nm)/BPhen (30 nm)/CBP: 8wt% Ir(ppy)₃ (10 nm)/TAPC (50 nm)/WO₃ (5 nm)/Ag (150 nm) multilayers. In this device structure, the WO₃/Ag/WO₃ (WAW) multilayer serving as a transparent cathode demonstrates a low sheet resistance (3.5 Ω/sq) and high optical transmittance (approximately 80%) in a visible light range of 400–600 nm; this multilayer was prepared by thermal evaporation to form a relatively smooth morphology of the conductive thin film on the glass substrate. In addition, an electron-only WAW device was subjected to electrical characterization, and the results revealed that this device exhibited a more efficient electron injection property at the WAW/BPhen:CS₂CO₃ interface than the contact electrode of a standard ITO-based device.     

A two-wavelength, passively self-injection locked, CW Ti3+:Al2O3 laser

We have demonstrated that passive self-injection control is very effective in a CW Ti³⁺:Al₂O₃ laser to produce high efficiency (η~15%), narrow-line, two-wavelength emission. Light reinjection is achieved with an original high-resolution two-wavelength selector combining an interference wedge and a grazing incidence grating. The device operates outside the main nonselective laser cavity; thus avoiding insertion losses and optical damage problems. A 1.5 W, background free, total output power has been obtained simultaneously at two narrow laser lines (fwhm: 8 pm), independently tunable over 50 mn. The two laser lines can be emitted in a single beam or in two separated beams. Self-injection wavelength control has been demonstrated both for linear and for ring laser cavities. In the latter case, unidirectional behavior is also obtained in the same way. Single-step (5s²S_1/2-5P²P_1/2,3/2 ) and two-step (5s²S_1/2-5p²P_3/2-5d² D_3/2,5/2) excitation of atomic rubidium vapor has been performed with our original laser device