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The Rayleigh band and the extra Raman-forbidden infrared active modes observed provide evidence for the existence of disorder in the system, apparently associated with grain structure, and lattice defects.
Introduction Over the last decades, a number of papers have been published addressed to the study of the dielectric properties in both pure and doped SrTiO3, KTaO3 and CaTiO3 compounds.
Great attention has been paid lately to the study of SrTiO3 ceramics, although the values of the dielectric permitivity at low temperatures are several times smaller in ceramics than in single crystals, and the microwave losses in ceramics are higher and grain size dependent.
The lower permittivity, which implies a smaller softening of the soft mode, is established to be mainly related to the existence of micro-polar regions in undoped STO ceramics, apparently due to frozen dipole moments at the grain boundaries.
Recently detailed pyroelectric thermal cycles and dielectric measurements carried out in La doped STO ceramics[1], with general formulae Sr(1-1.5x)LaxTiO3, reveal a complex non-ergodic behaviour related to the existence of different relaxations processes related to bulk and grain boundary dipoles and surface charge release.

The constructed models were used for the solution of a number of problems of dynamic and shock wave deformation [21, 23, 26, 27].
Here the element of a material is represented in the form of a number of chaotically oriented grains.
Calculation stress-strain state in grains carried out with model of a viscoelastic body.
Parameters of state the mesovolume including rather large number of grains, are averaged.
In Fig. 5 are shown calculations results [29] in which is compared character of deformation under the influence of a shock impulse (it is shown by the continuous line in Fig. 5 (a)) the same material with small (the size of grains of 50 microns, the left column) and large (the size of grains of 500 microns, the right column) grain size.

This in turn will increase the quantity of nuclei that grows individually, thus forming finer grains upon deposit [10,11].
Based on the relationship between carrier mobility and grain size, a smaller grain size would result in lower carrier mobility, while a larger grain size would result in higher carrier mobility [12,13].
As a result of the deposition potential, lower number of grain boundaries per unit area was attained due to the larger grain size at lower deposition potentials as compared to higher deposition potentials.
These grain boundaries served as scattering centers for the motion of electrons.
Under low concentration, an increment in concentration increased the number of ions available for the charge transfer process to occur, thus resulting in a higher average current density of the electrodeposition process.

Due to limited availability of test material ofAl-Zr-foil a reduced number of geometries has been produced.
With increasing geometry number, the resulting minor strains decrease.
One explanation is the total amount of grains over the material thickness.
While the amount of surface grains is relatively large, due to the total amount of grains over the material thickness.
These grains have less strain hardening, because of less grain boundaries to the surrounding grains [12], which leads to smaller values of the FLCs.

Japan and Europe and other developed countries have successively in a large number of manpower material resources, carry out the study of AIN substrate material development, and achieved significant results.
The XRD pattern of AlN nano ceram AlN is presented in figure 3 - Mo SEM images on the surface of the nanocomposite ceramics, figure 4 shows the SEM pictures of pure AlN nano ceramic, through the comparison we can see the AlN - Mo nano ceramic surface than the AlN ceramics grains is large, the grain size of combination between more closely, compactness is better, this is because of the addition of Mo, can reduce grain defects, at the same time, the addition of Mo also make ceramic ductility was strengthened.
We adopted 30 ESEM XL - FEG SEM (accelerating voltage to 30 kv) of AlN nano ceramic scanning electron microscopy (SEM) appearance figure, we can see from the figure a diameter of 50 nm or so small grain, in the drawing out of the two grain diameter were 69.5 nm and 41.3 nm.
Found the sample is made by around 50 nm of small grain combine.
Prove that AlN Mo nano ceramic nano grain is bigger, the surface of the grain size of combination between more closely.

SiCp/Al composites belong to typical difficult machined materials for high stiffness and intension of the SiC grain.
And it also indicates the sharpness of grinding grain of working surface of grinding wheel.
The number of grinding grain per length of work-piece decreased with the velocity increasing of workbench, which made maximum cutting depth of single grain and volume of metal machined increase.
The grinding force increased including tangential grinding force and radial grinding force for the load increasing per grain.
The change of grinding force indicated that the sharpness of grinding grain under different parameters during the process of grinding SiCp/Al composites.

In addition, solid solutions with excellent ferroelectric properties can be formed by BFO and a number of other perovskite structure compounds [3~6].
The grains in the sintered body are also nearly cubic, but the grain size is in the range of 100~300nm as shown in Fig.2(c).
The grain size is in a wide rang of 0.15~1µm.
It indicated that the molar ratio of Fe and Bi has a great effect on the grain morphology.
The grain morphology may be broken by grinding.

Recently developed α-Sialon materials have some unique characteristics, such as high hardness and the potential to clean up grain boundary glass.
HIP 5 (slow cooling rate) and time of cooling increase with number of HIP.
Another observed difference is the ratio between the elongated and submicron globular grains.
Very high amount of elongated grains in the A057 - HIP4 sample have negative influence on and cutting performance.
Positive influence on cutting performance: • pure α-Sialon with good ratio between elongated and submicron grains • pure β-Sialon with good ratio between elongated and submicron grains • homogeneity of the microstructure (no defect).

., characterized by compressive stresses, small grain sizes, or metastable phases, their thermal stability is of vital importance.
It can be seen that the there were some coarser grains embedded in the matrix grains for the Cr-Al-N coating deposited under larger chromium target power (Fig. 2(a)).
When the power applied on the chromium target changed from 120W to 90W, the grain sizes of the embedded grains became finer and the number of it decreased (Fig. 2 (b)).
The embedded grains showed (111) preferred orientation characteristic, which consisted with the results of XRD analysis.
Further decreasing the power applied on the chromium target, the embedded coarser grains vanished.

The microstructure of both materials is characterized by dendritic grains, carbides and casting defects.
The microstructure study of both alloys reveals coarse dendritic grains with carbides, eutectics and shrinkage pores (Fig. 1a).
An average grain size of IN 713LC (MAR-M247) was 0.66 mm (2.3 mm) established using linear intercept method.
Microstructure and precipitates morphology of (a) IN 713LC and (b) MAR-M247 Results The cyclic hardening/softening curves were obtained by plotting the stress amplitude versus the number of elapsed cycles.
They are depicted as the dependence of the plastic strain amlitude and the stress amplitude, respectively, established at half life versus the number of cycles to failure for both materials.