Anisotropy of Microhardness Crystals of the Langasite Family

Kugaenko, O. M.; Торшина, Е. С.; Petrakov, V. S.; Бузанов, О. А.; Sakharov, S.

doi:10.17073/1609-3577-2014-3-174-182

Cited by 4 publications

(3 citation statements)

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“…In addition to electrophysical properties, anisotropy was found in trigonal La 3 Ga 5 SiO 14 crystals in the measurements of mechanical (microhardness, thermal expansion coefficient, elastic coefficients) and thermal (thermal conductivity) properties [16][17][18][19][20].…”

Section: Discussion Of Resultsmentioning

confidence: 99%

“…As distinct from the studies of optical, mechanical and thermal properties [7,13,[16][17][18][19][20][21], so far there is insufficient data about the electrical conductivity and anisotropy mechanism for langasite crystals. Electrical conductivity of lanthanum gallium silicate is low and its value limits the operation reliability of piezoelectric element in different devices.…”

Section: Introductionmentioning

confidence: 99%

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Electrical conductivity and structural conditionality of ion transfer in langasite La-=SUB=-3-=/SUB=-Ga-=SUB=-5-=/SUB=-SiO-=SUB=-14-=/SUB=-:Mn

Sorokin

Golovina

Константинова

2022

Physics of the Solid State

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The temperature dependence of the static electrical conductivity sigmadc(T) of a single crystal of lanthanum gallium silicate (langasite) La3Ga5SiO14 activated with an impurity of Mn (1000 ppm) has been studied by impedance spectroscopy. Impedance measurements of La3Ga5SiO14 (sp. gr. P321, Z=1) were carried out along crystallographic axes a (double symmetry axis) and c (triple symmetry axis). It was found that the values of sigma|| a are significantly higher than the electrical conductivity sigma|| c, the anisotropy of the electrical conductivity is sigma|| a/sigma|| c=170 at 773 K. The activation energy of electrotransport is Esigma=0.75±0.05 and 1.09±0.02 eV along the a and c axes, respectively. The electrical conductivity mechanism has an ionic nature and an impurity character; oxygen vacancies VOoo are the most probable current carriers. Keywords: lanthanum gallium silicate, langasite family, single crystal, electrical conductivity, anisotropy.

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Section: Discussion Of Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electrical conductivity and structural conditionality of ion transfer in langasite La-=SUB=-3-=/SUB=-Ga-=SUB=-5-=/SUB=-SiO-=SUB=-14-=/SUB=-:Mn

Sorokin

Golovina

Константинова

2022

Physics of the Solid State

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“…To fabricate a sensing element for use in pressure gages one should mechanically treat langatate crystals (cutting, polishing and grinding). How there are but scarce data on the mechanical properties of langatate crystals [8][9][10][11]. Langatate crystals have anisotropic microhardness but data of different reports scatter significantly (Table 1).…”

Section: Introductionmentioning

confidence: 99%

Effect of growth conditions on the mechanical properties of lanthanum-gallium tantalate crystals

Weintraub¹,

Козлова²,

Забелина³

et al. 2020

MoEM

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The effect of growth conditions, anisotropy and polarity of specimens on the mechanical properties of lanthanum-gallium tantalate La3Ta0.5Ga5.5O14 single crystals grown in different atmospheres (argon (Ar), argon with oxygen addition (Ar+(<2%)O2 and Ar+(2%)O2) and air) was studied. The test specimens for the measurements were cut perpendicularly to a 3rd order axis (Z cuts) and in polar directions perpendicular to a 2nd order axis (Y cuts). The polarity of the Y cut specimens was tested by piezoelectric response. The brittleness was evaluated by microindentation at 3, 5, 10 and 25 g loads. The brittleness proved to show itself at a 5 g and the higher loads regardless of growth atmosphere. Therefore microhardness tests were done at loads of within 3 g. The microhardness HV of the specimens was measured with an DM 8B Affri microhardness tester by Vickers methods. The hardness H, elastic modulus E and elastic recovery coefficient R were measured with a Berkovich pyramid on a CSM Nano-Hardness Tester using the instrumented indentation (nanoindentation) method. Growth atmosphere was shown to affect the mechanical properties of lanthanum-gallium tantalate crystals: crystals grown in an oxygen-free argon atmosphere had the lowest microhardness, hardness, elastic modulus and elastic recovery coefficient. The lowest microhardness was detected in Z cut specimens regardless of growth atmosphere. The mechanical properties of polar Y cuts proved to be anisotropic: the microhardness, hardness, elastic modulus and elastic recovery coefficient of these cuts were lower for positive cuts than for negative ones regardless of growth atmosphere. Y and Z cut langatate specimens grown in argon with less than two percent oxygen exhibited strong elastic modulus and elastic recovery coefficient anisotropy.

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Structure and Optical Properties of Langasite Family Crystals (La1–xNdx)3Ga5SiO14 (x = 0, 0.4, 0.6, 1)

Golovina,

Konstantinova,

Dudka

et al. 2023

Crystallogr. Rep.

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Anisotropy of Microhardness Crystals of the Langasite Family

Cited by 4 publications

References 0 publications

Electrical conductivity and structural conditionality of ion transfer in langasite La-=SUB=-3-=/SUB=-Ga-=SUB=-5-=/SUB=-SiO-=SUB=-14-=/SUB=-:Mn

Electrical conductivity and structural conditionality of ion transfer in langasite La-=SUB=-3-=/SUB=-Ga-=SUB=-5-=/SUB=-SiO-=SUB=-14-=/SUB=-:Mn

Effect of growth conditions on the mechanical properties of lanthanum-gallium tantalate crystals

Structure and Optical Properties of Langasite Family Crystals (La1–xNdx)3Ga5SiO14 (x = 0, 0.4, 0.6, 1)

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