scholarly journals Mechanochemical synthesis of Pb2MgWO6 piezoceramics with alloying additives

2021 ◽  
Vol 340 ◽  
pp. 01008
Author(s):  
Natalya S. Shevchenko ◽  
Alexey A. Gusev
Keyword(s):  
Mechanochemical Synthesis ◽  
Mechanochemical Activation ◽  
Temperature Range ◽  
Alloying Additives

Pb2MgWO6 was prepared using mechanochemical activation and sintering in a temperature range of 600-1000ºÑ in three ways: 1) from oxides of the corresponding metals, 2) using MgWO4 precursor; and 3) in the presence of over-stoichiometric amounts (1wt.% and 2wt.% ) of Li2CO3 alloying additive.

scholarly journals Dielectric investigations of BiFeO3 ceramics

2009 ◽  
Vol 3 (1-2) ◽  
pp. 85-87 ◽  
Author(s):  
Simonas Greicius ◽  
Juras Banys ◽  
Izabela Szafraniak-Wiza
Keyword(s):  
Activation Energy ◽  
Dielectric Permittivity ◽  
Mechanochemical Synthesis ◽  
Synthesis Method ◽  
High Conductivity ◽  
Conductivity Activation Energy ◽  
Temperature Range ◽  
Conductivity Mechanism

In this paper we present the results from the investigation of the dielectric permittivity of BiFeO3 ceramics, prepared by mechanochemical synthesis method in a broad frequency and temperature range. The dielectric permittivity is mainly caused by high conductivity, which is suppressed in the frequencies above 1 MHz. The investigated ceramics showed conductivity activation energy E/k = 11280?12 K, and ?0 = 54161?800 S. The plots of M*revealed conductivity mechanism with ?0 = 1.12?10-13s, and E/k = 9245 K. .

scholarly journals Fracture, grinding, mechanical activation and synthesis processes in solids under mechanical action

2005 ◽  
Vol 37 (2) ◽  
pp. 93-105 ◽  
Author(s):  
M.V. Chaikina ◽  
Sergej Aman
Keyword(s):  
Mechanical Activation ◽  
Mechanochemical Synthesis ◽  
Mechanochemical Activation ◽  
Mechanical Action ◽  
Multicomponent Systems ◽  
Chemical Changes

The parameters of mechanical action on solids were determined for apatite and quartz as examples, providing separation between fracture, grinding and mechanical activation processes in solids. The texture, structural and chemical changes accompanying these processes in the samples under investigation are shown. The data on mechanochemical synthesis of isomorphous apatite modifications in multicomponent systems are reported. A reversible character of mechanochemical activation and mechanochemical synthesis is discovered.

MECHANOCHEMICAL SYNTHESIS OF FLUORIDATED HYDROXYAPATITE NANOPOWDER

2008 ◽  
Vol 22 (18n19) ◽  
pp. 3099-3106 ◽  
Author(s):  
M. H. FATHI ◽  
E. MOHAMMADI ZAHRANI
Keyword(s):  
Grain Size ◽  
Ftir Spectroscopy ◽  
Mechanochemical Synthesis ◽  
Ball Mill ◽  
Rotation Speed ◽  
Mechanochemical Activation ◽  
Mechanochemical Reaction ◽  
Fluoridated Hydroxyapatite ◽  
Lower Solubility ◽  
Bone Apatite

Recently fluoridated hydroxyapatite (FHA) has been developed since it possesses lower solubility than pure hydroxyapatite (HA), while maintaining the comparable bioactivity and biocompatibility in dental and orthopedic application. The aim of this work was to synthesize and characterize the FHA nanopowder via mechanochemical activation method. Mechanochemical reaction was performed in the planetary ball mill at 300 rpm rotation speed by using 8 balls with 2 cm diameter. XRD technique was used to evaluate phase and composition and determine the grain size of prepared FHA nanopowder. FTIR spectroscopy was utilized to identify the functional groups and to compare obtained powder with bone apatite. The results showed that the synthesis of FHA after 6 hr ball milling at 300 rpm was completed. Fluorhydroxyapatite grain size was almost 37nm after 6 hr of milling.

Mechanochemical activation of aluminum. 4. Kinetics of mechanochemical synthesis of aluminum carbide

2006 ◽  
Vol 68 (4) ◽  
pp. 470-480 ◽  
Author(s):  
A. N. Streletskii ◽  
I. V. Povstugar ◽  
A. B. Borunova ◽  
S. F. Lomaeva ◽  
P. Yu. Butyagin
Keyword(s):  
Mechanochemical Synthesis ◽  
Mechanochemical Activation ◽  
Aluminum Carbide ◽  
Kinetics Of

scholarly journals Comparison of Electrophysical Properties of PZT-Type Ceramics Obtained by Conventional and Mechanochemical Methods

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3301 ◽  
Author(s):  
Dariusz Bochenek ◽  
Przemysław Niemiec ◽  
Izabela Szafraniak-Wiza ◽  
Grzegorz Dercz
Keyword(s):  
Low Temperature ◽  
Technological Process ◽  
Mechanochemical Synthesis ◽  
Mechanochemical Activation ◽  
Piezoelectric Transducers ◽  
Ceramic Technology ◽  
Synthesis Process ◽  
Electrophysical Properties ◽  
Ceramic Samples ◽  
Sintering Method

In the paper, the multicomponent PZT-type ceramics with Pb(Zr0.49Ti0.51)0.94Mn0.015Sb0.01W0.015Ni0.03O3 composition have been obtained by conventional and mechanochemical methods. With conventional ceramic technology, PZT-type ceramics have been synthesized by the method of calcination powder (850 °C/4 h). Instead of this step, the mechanochemical synthesis process for different milling periods (15 h, 25 h, 50 h, 75 h) has been applied for a second batch of samples. To obtain the dense PZT-type ceramic samples, powders have been sintered by free sintering method at conditions of 1150 °C/2 h. Studies have shown that the perovskite structure of the PZT-type material is formed during mechanochemical activation of powders during the technological process at low temperature. The application of the mechanochemical synthesis to obtain the PZT-type materials also allows shortening of the technological process, and the useful electrophysical properties of ceramic samples are not reduced at the same time. The presented results have confirmed that the investigated materials can be used in microelectronic applications, especially as elements of actuators and piezoelectric transducers.

Defects in ion implanted silicon

1978 ◽  
Vol 36 (1) ◽  
pp. 386-387
Author(s):  
J.A. Lambert ◽  
P.S. Dobson
Keyword(s):  
Defect Structure ◽  
Dislocation Loops ◽  
Frank Loop ◽  
Burgers Vector ◽  
Temperature Range ◽  
Perfect Dislocation ◽  
Contrast Analysis ◽  
Image Position ◽  
Ion Implanted

The defect structure of ion-implanted silicon, which has been annealed in the temperature range 800°C-1100°C, consists of extrinsic Frank faulted loops and perfect dislocation loops, together with‘rod like’ defects elongated along <110> directions. Various structures have been suggested for the elongated defects and it was argued that an extrinsically faulted Frank loop could undergo partial shear to yield an intrinsically faulted defect having a Burgers vector of 1/6 <411>.This defect has been observed in boron implanted silicon (1015 B+ cm-2 40KeV) and a detailed contrast analysis has confirmed the proposed structure.

Domain coarsening by grain boundary migration in ordered Ni4Mo

1986 ◽  
Vol 44 ◽  
pp. 560-561
Author(s):  
K. Vasudevan ◽  
H. P. Kao ◽  
C. R. Brooks ◽  
E. E. Stansbury
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Short Range ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Rapid Cooling ◽  
Temperature Range ◽  
Fee Structure ◽  
Domain Coarsening ◽  
Boundary Reaction

The Ni4Mo alloy has a short-range ordered fee structure (α) above 868°C, but transforms below this temperature to an ordered bet structure (β) by rearrangement of atoms on the fee lattice. The disordered α, retained by rapid cooling, can be ordered by appropriate aging below 868°C. Initially, very fine β domains in six different but crystallographically related variants form and grow in size on further aging. However, in the temperature range 600-775°C, a coarsening reaction begins at the former α grain boundaries and the alloy also coarsens by this mechanism. The purpose of this paper is to report on TEM observations showing the characteristics of this grain boundary reaction.

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