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Lead-free piezoelectric ceramics [(Ba 0.85 Ca 0.15 )(Ti 0.90 Zr 0.10 )O 3- xBiErO 3 (BCTZ-xBE)] doped with a new doping material BiErO 3 (BE) has been synthesized successfully via solid state reaction technique, and their structural, dielectric, ferroelectric, and piezoelectric properties have been investigated. A high dielectric constant with very low dielectric loss and high remnant polarization followed by a low coercive field has been obtained with the addition of x = 0.5 BE. Bulk ferroelectric hysteresis loops were obtained with a maximum polarization P max = 26.7 μC/cm 2 and a saturation polarization P s = 16.65 μC/cm 2 along with a coercive field of E c ≈ 2.45 kV/cm. Results demonstrate an induced-strain increasing from ~ 0.11 to ~ 0.24 for x = 0.5, excellent piezoelectricity with d 33 = 560 pC/N, k p = 56%, Q m = 196, e m = 11,200 and tan δ = 0.01.

(100)- and (111)-oriented epitaxial Pb(Mg 1/3 Nb 2/3 )O 3 films with 500 and 1300 nm in thickness were grown by metal organic chemical vapor deposition. Remained strain was almost relaxed because the crystal structure of the films was almost the same as that of bulk Pb(Mg 1/3 Nb 2/3 )O 3 . Relative dielectric constant showed the maximum value against the temperature that depended on the measurement frequency. Maximum relative dielectric constant, e r (max.), and the temperature showing e r (max.), T (max.), decreased and increased with the frequency, respectively, are in good agreement with reported data for the bulk. e r (max.) and T (max.), respectively increased and decreased with the film thickness and (111)-oriented films showed larger value than that of the (100)-oriented one. Ferroelectricity was observed for all films up to 297 K and monotonously decreased with increasing temperature. Saturation polarization value increased with the film thickness and (111)-oriented films showed larger value than (100)-oriented ones. On the other hand, the coercive field decreased with increasing film thickness, but was almost independent with the film orientation.

Amorphous ribbons of composition Fe 85.2-x Co x Si 0.5 B 9.5 P 4 Cu 0.8 (x = 0 at% and 4 at%) have been flash annealed for 10 s at temperatures between 350 °C and 540 °C. Above about 400 °C a nanocrystalline state of bcc Fe(Co) is formed with a crystalline fraction of 50–55% and grain sizes of about 16–18 nm. The optimum nanocrystalline state reveals a saturation polarization up to J s =1.82 T–1.83 T and a coercivity as low as 3–5 A m −1 . The present paper complements the so far missing magnetostriction data for these alloys. Magnetostriction decreases from initially 40 ppm in the as cast amorphous state to about 14 ppm (x = 0 at%) and 19 ppm (x = 4 at%), respectively, after formation of the fully developed nanocrystalline state.

We applied Vopsaroiu's model to (Bi,Pr)(Fe,Mn)O3 (BPFM) and Pb(Zr,Ti)O3 (PZT) ferroelectric thin films fabricated by chemical solution deposition. The temperature dependences of the saturation polarization and the coercive field were measured in a low-temperature region from 100 to 200 K. The saturation polarizations of BPFM thin films decreased on decreasing the measurement temperature due to the polarization pinning effect, while that of PZT thin film was almost unchanged over the temperature region. The coercive fields of all the thin films were increased linearly on decreasing the measurement temperature. The activation energies for polarization reversal in as-grown BPFM, postannealed BPFM, and PZT thin films were 1.18, 1.25, and 0.95 eV, respectively. These results indicate that BPFM thin films have large activation energies for polarization reversal compared with PZT thin films. In addition, the postannealed BPFM thin film has a larger activation energy than the as-grown BPFM thin film.

Temperature-dependent ferroelectric dynamic hysteresis properties of modified Pb(Mg1/3Nb2/3)O3–Pb(Zr,Ti)O3 (PMN–PZT) ceramics have been investigated in a wide range from 298 to 433 K. Interestingly, it was found that back-switching polarization Pbc increased while the hysteresis area 〈A 〉, coercive field Ec, saturation polarization Ps, and remnant polarization Pr all decreased linearly with temperature below 398 K (close to the macro–micro domain transition temperature Tnr). A set of simple linear temperature scaling relations was established, which is different from the power-law scaling relations for soft and hard PZT ceramics. At further increased temperature, double-loop features appeared and the ferroelectric properties varied nonlinearly due to the reversible macro–micro domain transition in the T > Tnr region. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

0.95 (Na0.5Bi0.5)TiO3–0.05 BaTiO3 + 2 wt% Bi2O3 (NBT–BT3) ceramic was used as a target and NBT–BT3 thin films were deposited at room temperature by changing the RF power from 75 W to 150 W. The thickness of the NBT–BT3 thin films increased from 203 to 478 nm as the RF power increased from 75 W to 150 W. At 75 W RF power, the deposited NBT–BT3 thin films displayed defective surfaces, whereas at RF power ≧ 100 W, the NBT–BT3 thin films displayed smooth surfaces. The grain sizes also increased with increasing RF power. In addition, the remanent polarization and saturation polarization increased with increasing RF power. The coercive field first increased, reached a maximum at 100 W, then decreased with increasing RF power.

In this study, SrBi4Ti4O15 (SBT) thin films were deposited onto the SiO2/p-Si(100) and Pt/Ti/SiO2/p-Si(100) substrates by using sol-gel method. After deposition, the SBT thin films were then heated by a rapid thermal annealing (RTA) process conducted in air for 1min at 600-800°C. The surface morphologies and the crystalline structures of the SBT thin films were investigated by using SEM and XRD patterns. The grain sizes increased and the pores decreased with rising RTA temperature. In addition, the coercive field decreased and the remanent polarization and saturation polarization increased with rising RTA temperature. The lnJ-E1/2 curves of the SBT thin films were also investigated to find the leakage current mechanisms correspond either to the Schottky emission or to the Poole-Frenkel emission.

Soft magnetic composites containing an organic binder and mixtures of two different soft magnetic particles – iron and nano-crystalline Fe73.5Si15.5B7Cu1Nb3 – in varying mixing ratios have been prepared at a total filler fraction x mag = 0.5 and examined regarding the magnetic properties. Results show that the coercivity is decreased by replacing the magnetically harder material with the magnetically softer material in the composite until a certain threshold value of the mixing ratio is reached. Above this threshold the coercivity stays nearly constant. Total losses P / f , saturation polarization J s and inner demagnetization factor N i follow a linear mixing rule. The composite’s permeability μ is a result of filler fraction, mixing ratio, coercivity, polarization and inner demagnetization factor and due to that complex dependence hardly predictable.

Effects of compressive stress on the ferroelectric properties of ceramics in PZT–PZN systems were investigated. (1 − x )Pb(Zr 1/2 Ti 1/2 )O 3 ( x Pb(Zn 1/3 Nb 2/3 )O 3 or (1 − x )PZT–( x )PZN ( x = 0.1–0.5) ceramics were prepared by a conventional mixed-oxide method. The ferroelectric properties under compressive stress of the PZT–PZN ceramics were observed at stress levels up to 170 MPa using a compressometer in conjunction with a modified Sawyer–Tower circuit. It was found that with increasing compressive stress the area of the ferroelectric hysteresis (P–E) loops, the saturation polarization ( P sat ), the remanent polarization ( P r ), and the coercive field ( E c ) decreased. These results were interpreted through the non-180° ferroelectric domain switching processes.

Effects of compressive stress on the ferroelectric properties of ceramics in PZT–PZN system were investigated. The ceramics with a formula (1− x )Pb(Zr 1/2 Ti 1/2 )O 3 – x Pb(Zn 1/3 Nb 2/3 )O 3 or (1− x )PZT–( x )PZN ( x = 0.1–0.5) were prepared by a conventional mixed-oxide method. The ferroelectric properties under the compressive stress of the PZT–PZN ceramics were observed at the stress levels up to 170 MPa using a compressometer in conjunction with a modified Sawyer–Tower circuit. It was found that with increasing compressive stress the area of the ferroelectric hysteresis ( P – E ) loops, the saturation polarization ( P sat ), the remnant polarization ( P r ), and the coercive field ( E c ) decreased. These results were interpreted through the non-180° ferroelastic domain switching processes.

In this work, effects of compressive stress on the ferroelectric properties of 0.7PMN–0.3PT ceramics were investigated. The ceramics with the formula (0.7)Pb(Mg1/3Nb2/3)O3-(0.3)PbTiO were prepared by a conventional mixed-oxide method. The ferroelectric properties under compressive stress were observed at stress up to 80 MPa using a compressometer in conjunction with a modified Sawyer-Tower circuit. The results showed that applied stress had a significant influence on the ferroelectric properties of 0.7PMN–0.3PT ceramics. Ferroelectric characteristics, i.e. the area of the ferroelectric hysteresis (P-E) loop, the saturation polarization (Psat), the remanent polarization (Pr) and loop squareness (Rsq), decreased with increasing compressive stress, while the coercive field (Ec) remained relatively constant. Stress-induced domain wall motion suppression and non-180oC ferroelectric domain switching processes are responsible for the changes observed.

Substituted M-type ferrite BaFe12−2x(Me1Me2)xO19, 0 ≤ x ≤ 0.6 was prepared by both mechanical alloying and precursor method, where Me1 = Co, Ni, Zn, Sn and Me2 =Ru, Ti, Zr, Sn. Magnetic phase purity, change of saturation polarization, Curie temperature, coercivity and magnetic susceptibility was studied as function of x. Attention was focused to results obtained for (NiRu)x, (ZnRu)x, and (SnRu)x mixtures with low doping ratio x.

A sol-gel technology to fabricate PZT thick film for cantilever beam was investigated. In this process, PZT nano-powder is dispersed into a PZT sol solution, which is identical with the powder in composition, and then the PZT suspension and clean PZT sol solution were deposited alternately on an Au/Cr/SiO2/Si substrate using spin-coating route. Above process was repeated in order to deposit the desired thickness. The results showed that the perovskite PZT thick film with thickness of about 4 μm was obtained after annealing at 650 °C for 2 h and it has the saturation polarization of 54 μC/cm2, the remnant polarization of 30 μC/cm2 and the coercive field of 50 kV/cm.

NdFeB films are prepared by dc sputtering. The dependence of the film properties on sputtering parameters is investigated by analysing the surface morphology, crystalline structure, and magnetic properties for different preparation conditions. c-textured films are prepared with a coercivity of up to 0.2 T, a saturation polarization of 1.6 T, and a remanent polarization of 0.4 T. Special emphasis is given to the preparation conditions such that the surface roughness of films with sufficient magnetic performance is well below 100 nm, making these films suitable for micropatterning. NdFeB-Schichten werden mittels dc-Kathodenzerstaubung prapariert. Fur unterschiedliche Praparationsbedingungen beim Sputterprozes werden die Schichteigenschaften hinsichtlich Oberflachenmorphologie, Kristallstruktur und magnetischem Verhalten untersucht. Es konnen Filme mit c-Achsen-Textur hergestellt werden, welche eine Koerzitivkraft von 0,2 T, eine Sattigungsmagnetisierung von 1,6 T und eine Remanenz von 0,4 T aufweisen. Die Praparationsbedingungen werden insbesondere daraufhin variiert, das eine Oberflachenrauhigkeit der Filme bei Wahrung ausreichender magnetischer Eigenschaften von unter 100 nm erreicht wird. Hierdurch werden diese Filme fur Zwecke der Mikrostrukturierung geeignet.

For the present study, La substituted PZT ceramics having compositional formula Pb1−3x/2LaxZr0.65Ti0.35O3 were prepared by conventional solid state method. La content was varied from x = 0 to 0.03 in the steps of 0.01. XRD analyses of all the samples were done and were found to have single phase with rhombohedral structure. In this paper, we are reporting the variation in ferroelectric properties of Pb1−3x/2LaxZr0.65Ti0.35O3 by varying La content. P‐E hysteresis loops were recorded using P‐E loop tracer based on Sawyer‐ Tower circuit for all the samples at 20 Hz. Increase in coercive field (Ec), remanant polarization (Pr), saturation polarization (Ps) and squareness ratio (Pr/Ps) was observed with increase in x.

A methodology to fabricate ultrasoft CoFe nano-/microfilms directly via electrodeposition from a semineutral iron sulfate solution is demonstrated. Using boron-reducer as the additive, the CoFe films become very soft with high magnetic moment. Typically, the film coercivity in the easy and hard axes is 6.5 and 2.5 Oersted, respectively, with a saturation polarization up to an average of 2.45 Tesla. Despite the softness, these shining and smooth films still display a high-anisotropic field of ~45 Oersted with permeability up to 104. This kind of films can potentially be used in current and future magnetic recording systems as well as microelectronic and biotechnological devices.

Highly (100) oriented Pb(Zr0.53Ti0.47)O3 (PZT) films were prepared on Si substrates with ultrathin SiO2 buffer layer by pulsed laser deposition. Hysteresis measurements show that saturation polarization, remnant polarization and coercive field of the films reach 26 μC/cm2, 10 μC/cm2 and 70 kV/cm, respectively. The thickness of SiO2 buffer layer is found to play a significant role on phase purity and orientation of PZT as well as the prevention of interdiffusion. It is also found that the grain size and the interdiffusion between PZT and Si are the key factors for the ferroelectric properties of the films, which are discussed together with the synthesis condition in detail.

The dielectric properties of electrooptic thin films were varied by altering the stresses placed upon the films. Selected thin films in the lanthanum-modified lead zirconate titanate system (PLZT) were produced by using the dip-coating process and applying various stresses. Comparisons were made among thin films under mechanically applied stresses of different magnitude. Properties measured were dielectric constant, saturation polarization, remanent polarization, coercive field and d-spacing. The effects of the applied stresses on the physical and electrical properties of the films are discussed.

Ferroelectric properties were investigated for (100), (110), and (111)-single-oriented rhombohedral Pb(Zr0.65Ti0.35)O3 films. Saturation polarization, P sat, was changed by the simple tilting angle of the polar axis from the film surface normal. On the other hand, (100)- and -oriented films prepared on (100) Si substrates showed similar P sat values due to the coexistence of orientation. The coercive field, E c, of rhombohedral Pb(Zr0.65Ti0.35)O3 films was lower than that of tetragonal Pb(Zr0.4Ti0.6)O3 films. (100)-oriented rhombohedral films with SrRuO3 electrodes did not show noticeable degradation in polarization up to 1010 switching cycles. These results show that (100)-oriented rhombohedral Pb(Zr x Ti1− x )O3 film is available to realize the low voltage operated ferroelectric random access memory instead of the present tetragonal Pb(Zr x Ti1− x )O3 films.

The effect of a partial substitution of Nd by Y on the properties of sintered Nd 15- x Y x Fe 77 B 8 magnets has been investigated. With increasing Y concentration the density of the magnets decreases slowly, whereas the saturation polarization and the Curie temperature are not changed significantly. The decrease of the coercivity is correlated with the decrease of the anisotropy field strength.

Dielectric hysteresis in manganese dioxide has been studied in d.c. and a.c. fields as a function of temperature and the biassing field. At a temperature near 50°C., the dielectric constant is maximum and the loss factor tan δ is minimum. In the same temperature region, the saturation polarization, and the coercive field calculated from the hysteresis loop fall to a low value. These results give further indication of the ferroelectric properties of manganese dioxide.

Amorphous metal alloys were prepared using the roller quenching method. The composition Fe 40 Ni 40 P 14 B 6 was studied in more detail in view of applications as new magnetic materials. Remanence, coercivity and saturation polarization were found to be B r = 0,35 T; H c = 0,04 A/cm and B s = 0,71 T. The initial permeability was determined to μ i ≅ 400–600 and the maximum permeability to μ max ≅ 50 000. After thermal treatment, the data increased to μ i ≅ 3000 and μ max ≅ 65 000. The frequency dependence of the initial permeability was measured.