Elasticity and magnetism of Ni2 MnGa premartensitic tweed. Issue 10 (22nd April 2014)

• Record Type: Journal Article
• Authors: Seiner, Hanuš; Kopecký, Vít; Landa, Michal; Heczko, Oleg
• Is Part Of: Physica status solidi. Volume 251:Issue 10(2014:Oct.)
• Page Start: 2097
• Page End: 2103
• Publication Date: 2014-04-22
• Subjects: Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.201350415
• Languages: English
• ISSNs: 0370-1972

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="pssb201350415-sec-0001" sec-type="section"> <p>Magnetic, magneto‐elastic and elastic measurements were used to characterize the thermal evolution of the premartensite phase of Ni<sub>2</sub> MnGa. The premartensitic transition is shown to correspond to a sharp maximum of magnetostriction and a pronounced minimum of the (110) <inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh1fdds79m" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:15213951:media:pssb201350415:pssb201350415-math-0001" display="inline" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>〈</mml:mo><mml:mn>1</mml:mn><mml:mover accent="true"><mml:mn>1</mml:mn><mml:mo>‾</mml:mo></mml:mover><mml:mn>0</mml:mn><mml:mo>〉</mml:mo></mml:math></alternatives></inline-formula> shear stiffness (the <inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh1fdds76z" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:15213951:media:pssb201350415:pssb201350415-math-0002" display="inline" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>c</mml:mi><mml:mo>′</mml:mo></mml:msup></mml:math></alternatives></inline-formula> elastic coefficient); no additional softening of the <inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh1fdds6x1" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:15213951:media:pssb201350415:pssb201350415-math-0003" display="inline" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>c</mml:mi><mml:mo>′</mml:mo></mml:msup></mml:math></alternatives></inline-formula> coefficient prior to the martensitic transformation was observed. In contrast, a significant softening of the (100) <inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh1fdds6vx" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:15213951:media:pssb201350415:pssb201350415-math-0004" display="inline" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>〈</mml:mo><mml:mn>010</mml:mn><mml:mo>〉</mml:mo></mml:math></alternatives></inline-formula> stiffness (the <inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh1fdds72r" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:15213951:media:pssb201350415:pssb201350415-math-0005" display="inline" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>c</mml:mi><mml:mn>44</mml:mn></mml:msub></mml:math></alternatives></inline-formula> elastic coefficient) was observed in the vicinity of the martensitic transition, while this coefficient is fully unaffected by the premartensitic transition. A simple two‐dimensional model of the tweed is presented to explain this mutual independence between the <inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh1fdds716" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:15213951:media:pssb201350415:pssb201350415-math-0006" display="inline" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>c</mml:mi><mml:mo>′</mml:mo></mml:msup></mml:math></alternatives></inline-formula> and <inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh1fdds6st" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:15213951:media:pssb201350415:pssb201350415-math-0007" display="inline" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>c</mml:mi><mml:mn>44</mml:mn></mml:msub></mml:math></alternatives></inline-formula> shears and the effect of tweed formation on both of them.</p> </sec> </abstract>