Pure and fully texturized Sr2FeMoO6 thin films prepared by pulsed laser deposition from target made with citrate-gel method

Sr₂FeMoO₆ (SFMO) thin films were grown on SrTiO₃ and MgO single crystal substrates by pulsed laser deposition. The SFMO target with nanometer sized grains for the film preparation was made from powder prepared by citrate-gel method. The parameters for ablation were optimized and the importance of the substrate temperature is observed. Film quality was verified with various X-ray diffraction methods and magnetometric measurements. The films are pure, without impurities such as metallic iron, Fe₂O₃, SrMoO₃ or SrMoO₄ and they are completely c-axis oriented. The Curie temperature for the films is higher than room temperature.     

Effect of rare earth on physical properties of Na0.5Bi0.5TiO3 system: A density functional theory investigation

Na_0.5(Bi_3/4RE_1/4)_0.5TiO₃ (RENBT, RE = Nd, Gd, Dy, and Ho) compounds were investigated in the framework of first-principles calculations using the full potential linearized augmented plane wave (FP-LAPW) method based on the spin-polarized density functional theory implemented in the WIEN2k code. Combined charge density distribution and Ti K-edge X-ray absorption spectra reveal that the RENBT compositions with high polarization values are accompanied by a higher TiO₆ distortion, DyNBT, and NdNBT compounds. The effect of the rare-earth elements on the polarization is confirmed experimentally with the collection of the hysteresis loops. The investigation of the electronic properties of the compounds highlights the emergence of a magnetization owing to the 4f orbital effect of the rare-earth elements. Besides, the investigation of the chemical ordering shows a short-range chemical ordering for the pure composition and an increased A-site disorder for dysprosium doped NBT system. The increased disorder may speak for increased relaxor properties in the RE doped compositions.     

电磁型微马达的微转子研究

简要介绍了直径２ｍｍ电磁型微马达的结构和磁路。对微转子的设计和加工,多微磁极的写（充）入和均匀性进行分析和讨论。测量了不同充磁条件下的微转子剩余磁化强度和微转子之间的吸力。     

热压铸法制造石英钟钟表磁环的工艺研究

介绍了用热压铸法制造石英钟钟表磁环的工艺实验,确定了其最佳制造工艺方案,选择了最适宜的磁性粉,同时制造了简单而实用的充磁工装．     

On the separation of Lorentz and magnetization forces in the transduction mechanism of Electromagnetic Acoustic Transducers (EMATs)

Electromagnetic Acoustic Transducers (EMATs) are widely used in Nondestructive Evaluation (NDE) of metals, including the inspection of ferritic steels. Optimization of EMATs in ferromagnetic materials is often accomplished using computational simulations that account for the three main types of transduction mechanism, namely the effects of Lorentz forces, magnetization forces, and magnetostriction. The extensive literature on the Lorentz and magnetization mechanisms of EMATs has been historically scattered with alternative notations causing conflicting interpretations of the fundamental governing equations that often led to erroneous implementations of these equations in computational simulations. The purpose of this paper is to clarify this issue. The confusion is caused by the arbitrary nature of the separation of electromagnetic transduction force into Lorentz and magnetization components. This paper shows that apparently contradicting models are actually equivalent if the Lorentz and magnetization forces are chosen to correctly match each other, while mixing otherwise acceptable but mutually incompatible terms leads to unacceptable modelling errors. This paper also provides guidelines for the implementation of these transduction mechanisms in computational models for EMATs.     

磁处理对粘土吸附作用的影响

用分光光度计测试研究了磁处理对钻井液中粘土胶粒表面吸附处理剂的变化规律。结果表明,粘土胶粒经磁处理后吸附处理剂的量增加。利用热力学理论解释了吸附量增加的内在因素,提出磁处理使钻井液体系熵减小的理论。     

Observation of Local Magnetic Correlations in La2NiO4.18

We studied the magnetic correlations in polycrystalline La₂NiO_4+δ with δ=0.18 using electron spin resonance (ESR), which is a local magnetic probe, and magnetic susceptibility. Significant magnetic changes were observed around 160 K. Such changes can be related to the particular order of charge and spins present in this compound.     

磁化钻井液在中原油田的应用

磁化钻井液技术在中原油田十几口井中现场应用,取得了显著的效果。实践证明:钻井液经磁化处理后,性能得到了明显改善,井壁稳定性增强,维护处理周期延长,有较好的技术经济效益,可以推广应用。     

Effect of sintering on the magnetization behaviour of Mg x Zn(1 −x)Fe2O4 system

Magnesium zinc ferrites with the general formula Mg _x Zn_{(1 −x)}Fe₂O₄ were prepared by the standard ceramic technology route involving double sintering. X-ray analysis was carried out to confirm the single-phase formation as well as to calculate the lattice parameters. Two sets of samples were prepared by sintering the samples at 1100°C for 15 and 30 h respectively. The high-field loop tracer was used to measure the hysteresis parameters. It is observed that the sintering conditions effectively modify the magnetization characteristics of these ferrites.     

带磁切削机理及磁化处理的推广应用

通过对带磁切削的机理研究，发现磁化处理引起的磁致伸缩强化现象能够提高金属材料的强度、硬度及抗粘着磨损的能力，结合磨损的四种基本类型以及磁化处理的效果和可行性，认为磁化处理将是提高金属材料耐磨性的一种简单有效的新方法．