Mechano‐Synthesis of Lead–Magnesium–Niobate Ceramics

Abstract

The synthesis of Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) with high-energy milling was studied by X-ray powder diffraction (XRD) using the Rietveld-refinement method. The results are discussed in terms of the qualitative and quantitative composition of the crystalline and amorphous phases as a function of milling time. The mechano-synthesis of PbO, Nb 2 O 5 , and MgO leads to the formation of perovskite PMN. In the initial stage of milling, particle size reduction and a high degree of amorphization were observed, together with the simultaneous formation of perovskite and pyrochlore-type structures. A mechanism for the formation of PMN by the mechano-synthesis route is proposed.

Using Infrared Spectroscopy to Identify New Amorphous Phases - A Case Study of Carbonato Complex Formed by Mechanochemical Processing

“…Therefore, the amorphous phase represents a transitional phase of the reaction. (Wang et al, 2000a(Wang et al, , 2000bKuscer et al, 2006). In order to understand mechanochemical reactions, it is thus indispensable to analyze more closely the transitional amorphous phase.…”

“…In addition to the amount of the crystalline phases, i.e., Na 2 CO 3 , Nb 2 O 5 and NaNbO 3 , we determined also the contribution from the XRD background, which we denoted as "XRDamorphous" phase. This was done using an internal standard method; details of the method can be found in Kuscer et al (2006) and Rojac et al (2008b).…”

Structural and phase evolution in mechanically alloyed calcium copper titanate dielectrics

“…3. The grain refinement rate of precursor materials is significantly different, possibly due to the difference in the crystalline lattice energy and melting point [21,39,40]. As a result of further milling, CCTO with an average crystallite size of 13 nm is formed and its crystallite size approaches 24 nm after 256 h of milling.…”

“…As a consequence, care should be taken whenever the method is used in materials processing. Recently, MA has been applied in the processing of ceramic materials such as lead zirconate titanate [13], lead zinc niobate [15], lead magnesium niobate [20,21], lead magnesium niobate-lead titanate [22,23], and barium titanate [14,20,24].…”

Integrated Powder-Based Thick Films for Thermoelectric, Pyroelectric, and Piezoelectric Energy Harvesting Devices

“…Te, Sb, Bi) are milled in an oxygen free environment to prevent oxidation. With oxide materials [43] oxygen need not be eliminated during the milling process. A high proportion of milling media (15-30 times the weight of powder) is used to ensure that the starting powders are reduced in size through mechanical fracture and that sufficient energy is transferred to the powders to cause chemical blending.…”