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This paper presents the design, modeling and analysis of ferroelectric material based MEMs with finite element method. Microelectromechanical systems (MEMS) (also written as micro-electro-mechanical, MicroElectroMechanical or microelectronic and microelectromechanical systems) is the technology of very small mechanical devices driven by electricity. MEMS structures can be driven by thermal, electrostatic, magnetic, optical and pneumatic drivers. Detection process is usually is made via optical and electronic signals. In this study, modal and harmonic analysis of MEMS gyroscopes composed of ferroelectric materials is realized by Finite Element Analysis, and then their results are compared. Finite element analysis of solid gyroscopes made up of PZT-5J and PZT-5H materials were modeled and simulated. Modal and harmonic analysis were performed for two different models. As a result of the analysis, model 2 of solid gyroscopes made up ​​of PZT-5H more sensitive than the angular velocities were observed., Bu çalışmada sonlu elamanlar analizi (metodu kullanılarak) ile ferroelektrik (PZT) malzemeden yapılmış mikro-elektromekanik sistemlerin (MEMS) tasarımı, modellenmesi ve analizi yapılmıştır. Mikroelektro-mekanik sistemler (MEMS) günümüzde var olan mekanik ve elektrik sistemlerin entegre ve minyatürize versiyonları olup mikron boyutlarında olan sistemlerdir. MEMS yapıları termal, elektrostatik, manyetik, pnömatik ve optik olarak tahrik edilebilir. Algılama işlemi ise genellikle optik ve elektronik sinyaller vasıtası ile yapılır. Bu çalışmada, Sonlu Elemanlar Analizi ( metodu kullanılarak) ferroelektrik malzemelerden yapılan MEMS jiroskopun, modal ve harmonik analizleri yapılarak sonuçları karşılaştırılmıştır. Sonlu elemanlar analizi ile PZT-5J ve PZT-5H malzemelerinden yapılan solid jiroskopun modellenmesi ve simulasyonu yapılmıştır. İki farklı modelin modal ve harmonik analizleri yapılmıştır (incelenmiştir). Yapılan analiz sonucunda PZT-5H den yapılan model 2 deki solid jiroskopun açısal hızlara karşı daha hassas ölçüm yaptığı gözlemlenmiştir

The phase diagrams of the bilayer spin-(3)/(2) Ising model on the Bethe lattice is analyzed by taking into account the intralayer coupling constants of the two layers (J(1), J(2)), interlayer coupling constant between the layers (J(3)) and crystal field interaction (D) for the coordination number q = 3 by using the exact recursion equations. First, the distinct ground state phase diagrams of the model are obtained on the (J(2)/vertical bar J(1)vertical bar, J(3)/q vertical bar J vertical bar(1)) plane with J(1) > 0 for given crystal field values. Then, the phase diagrams of the system are obtained on the (kT/J(1),J(3)/J(1)) planes for given values of the crystal field and alpha = J(2)/J] on the honeycomb lattice, i.e., q = 3. It was found that the system presents both first- and second-order phase transitions, therefore, tricritical points, and splitting of the critical lines at negative values of the crystal field. The paramagnetic phases are also classified by studying the thermal variations of the quadrupolar moments. (c) 2007 Elsevier B.V. All rights reserved.

The spin-3/2 Ising model on the bilayer Bethe lattice is studied in terms of the exact recursion relations with the intralayer bilinear interactions J(11) and J(22) of the two layers with ferromagnetic coupling and interlayer bilinear interaction J(12) between the layers with ferromagnetic or antiferromagnetic coupling. We first have obtained the ground state configurations of the model on the (J(22)/vertical bar J(11)vertical bar,J(21)q/vertical bar J(11)) planes for J(11)< 0 and J(11)> 0. Then the thermal behaviors of the order-parameters, the total and staggered magnetizations of the two layers and also the spin-spin correlation function between the nearest-neighbor spins of the adjacent layers, are studied to obtain the phase diagrams of the model on the (kT/J(11),J(12)/J(11)) plane for given values of J(22)/J(11) and the coordination number q. As a result, a few types of the critical temperatures of the model are obtained. (c) 2006 Elsevier B.V. All rights reserved.