Structural and mechanical properties of sol-gel prepared pyrochlore lanthanum niobates

被引：10

作者：

Brunckova, H. ^{[1
]}

Medvecky, L. ^{[1
]}

Hvizdos, P. ^{[1
]}

Durisin, J. ^{[1
]}

Girman, V. ^{[2
]}

机构：

[1] Slovak Acad Sci, Inst Mat Res, Kosice 04001, Slovakia

[2] Safarik Univ, Fac Sci, Inst Phys, Kosice 04154, Slovakia

来源：

JOURNAL OF MATERIALS SCIENCE | 2015年 / 50卷 / 22期

关键词：

RARE-EARTH ORTHONIOBATE; FERROELASTIC LANBO4; BEHAVIOR; PHASE; TRANSFORMATION; INDENTATION; SUBSTRATE; POWDERS; SHAPE; LOAD;

D O I：

10.1007/s10853-015-9274-8

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Lanthanum orthoniobate LaNbO4 (LN) precursors were prepared by a modified polymeric complex sol-gel method using Nb-tartrate in different solvents (ethanol or methanol) with calcination at 750 A degrees C. The monoclinic LaNbO4 and orthorhombic LaNb5O14 phases were formed after annealing at 900 A degrees C from precursors synthesized in ethanol (LNet) and methanol (LNmet), respectively. FTIR and Raman spectra confirmed different structures of LN at 900 A degrees C in both solvents. The microstructures indicate the strong effect of solvents on surface morphology. TEM and SAED patterns verified the monoclinic LaNbO4 and orthorhombic LaNb5O14 phases with ferroelastic domains at 750 and 900 A degrees C, respectively. Mechanical characterization was conducted for the first time by nanoindentation on the sol-gel derived LN after annealing at a low temperature. The hardness and elastic modulus of LNmet (LNet) were measured to be similar to 2.6(1.5) and similar to 45(30) GPa, respectively. The modulus and hardness of LNmet were higher in comparison with LNet. The strong solvent effect on mechanical properties of lanthanum niobate was confirmed.

引用

页码：7197 / 7207

页数：11

共 37 条

[11] Low-temperature preparation of Ba5Nb4O15 ceramics through a sol-gel process [J].

Hsiao, Yu-Jen ;

Chang, Yen-Hwei ;

Chang, Yee-Shin ;

Fang, Te-Hua .

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 2007, 90 (07) :2287-2290

[12] ELECTRON BACK SCATTERING STUDY OF DOMAIN-STRUCTURE IN MONOCLINIC PHASE OF A RARE-EARTH ORTHONIOBATE LANBO4 [J].

JIAN, L ;

WAYMAN, CM .

ACTA METALLURGICA ET MATERIALIA, 1995, 43 (10) :3893-3901

[13] Monoclinic-to-tetragonal phase transformation in a ceramic rare-earth orthoniobate, LaNbO4 [J].

Jian, L ;

Wayman, CM .

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1997, 80 (03) :803-806

[14] Compressive behavior and domain-related shape memory effect in LaNbO4 ceramics [J].

Jian, L ;

Wayman, CM .

MATERIALS LETTERS, 1996, 26 (1-2) :1-7

[15] Antiferroelectric instability in double perovskite systems La(2-x)/3LixTiO3, La(1-x)/3LixTaO3 and La(1-x)/3LixNbO3. [J].

Laguna, MA ;

Sanjuán, ML .

FERROELECTRICS, 2002, 272 :63-68

[16] Structural and dielectric characteristics of barium lanthanum zinc niobate [J].

Lee, Chun-Te ;

Lin, Yi-Chang ;

Huang, Chi-Yuen ;

Su, Che-Yi ;

Hu, Chin-Li .

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 2006, 89 (12) :3662-3668

[17] Low-temperature sintering of temperature-stable LaNbO4 microwave dielectric ceramics [J].

Lee, Hang-Won ;

Park, Jeong-Hyun ;

Nahm, Sahn ;

Kim, Dong-Wan ;

Park, Jae-Gwan .

MATERIALS RESEARCH BULLETIN, 2010, 45 (01) :21-24

[18] Solid-State Synthesis and Structural Characterization of Hydrated Zinc (II) Tartrate Complex [J].

Li, Bei-Gang ;

Mi, Jing ;

Nie, Feng-Mei .

JOURNAL OF CHEMICAL CRYSTALLOGRAPHY, 2010, 40 (01) :29-33

[19] Infrared spectroscopy of aqueous carboxylic acids: Comparison between different acids and their salts [J].

Max, JJ ;

Chapados, C .

JOURNAL OF PHYSICAL CHEMISTRY A, 2004, 108 (16) :3324-3337

[20] High-temperature proton-conducting LaNbO4-based materials:: Powder synthesis by spray pyrolysis [J].

Mokkelbost, Tommy ;

Andersen, Oystein ;

Strom, Ruth Astrid ;

Wiik, Kjell ;

Grande, Tor ;

Einarsrud, Mari-Ann .

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 2007, 90 (11) :3395-3400

← 1 2 3 4 →