Consequences of sp2-sp3 boron isomerization in supercooled liquid borates

被引：7

作者：

Alderman, O. L. G. ^{[1
]}

Benmore, C. J. ^{[2
]}

Weber, J. K. R. ^{[2
,3
]}

机构：

[1] Rutherford Appleton Lab, ISIS Neutron & Muon Source, Sci & Technol Facil Council, Harwell Campus, Didcot OX11 0QX, Oxon, England

[2] Argonne Natl Lab, Xray Sci Div, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA

[3] Mat Dev Inc, Arlington Hts, IL 60004 USA

来源：

APPLIED PHYSICS LETTERS | 2020年 / 117卷 / 13期

关键词：

HIGH-RESOLUTION; CONFIGURATIONAL ENTROPY; BOROSILICATE; VISCOSITY; GLASSES; DYNAMICS; CONDUCTIVITY; COORDINATION; STRENGTH; MELTS;

D O I：

10.1063/5.0024457

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Time-resolved high-energy synchrotron x-ray total scattering measurements on supercooled molten lithium metaborate (LiBO2) reveal an isomerization reaction involving conversion of trigonal sp(2) boron to tetrahedral sp(3) boron during quenching and glass formation. Van't Hoff analysis yields an accurate enthalpy change, Delta H=21(1) kJ mol(-1) boron, from which we develop an analytical model for the sp(3) isomer fraction and its contribution to configurational heat capacity (C-p(conf)) and entropy as a function of temperature and composition. Isomerization constitutes 40% of the total calorimetric C-p(conf) at the glass transition for LiBO2 and directly contributes to the observed rise in liquid fragility with the lithium content.

引用

页数：5

共 43 条

[11] LITHIUM BORATE GLASSES - A QUANTITATIVE STUDY OF STRENGTH AND FRAGILITY [J].