• Phacheerak, Kanoknan
• Boonchun, Adisak
• Simalaotao, Kodchakorn
• Maluangnont, Tosapol
• Thanasarnsurapong, Thanasee

Abstract

<jats:title>Abstract</jats:title><jats:p>The elastic properties of the alkali hexatitanate family A<jats:sub>2</jats:sub>Ti<jats:sub>6</jats:sub>O<jats:sub>13</jats:sub> (A = H, Li, Na, K, and Rb) are investigated which based on Density Functional Theory (DFT) within Generalized Gradient Approximation plus Hubbard <jats:italic>U</jats:italic> (GGA+<jats:italic>U</jats:italic>) approach. The results showed that all members of the family are wide-band semiconductors and the calculated lattice parametersare consistent with experimental values. In terms of mechanical stability, the results indicated that the alkali hexatitanates are highly incompressible to uniaxial stress, with the largest elastic constant C<jats:sub>22</jats:sub> reaching values as high as 265 GPa inK<jats:sub>2</jats:sub>Ti<jats:sub>6</jats:sub>O<jats:sub>13</jats:sub>. The obtained elastic constants, using the stress-strain method, were used to calculate bulk modulus, shear modulus, Young's modulus, brittleness and ductility, elastic anisotropy, Vickers hardness, sound velocities, and the Debye temperature. It was found that the member of the family with the highest atomic number of the alkaline group,Rb<jats:sub>2</jats:sub>Ti<jats:sub>6</jats:sub>O<jats:sub>13</jats:sub>, had the highest values of bulk, shear, and Young's modulus, as well as the lowest values of shear and compression anisotropy, and a high Vickers hardness.&amp;#xD;</jats:p>

Topics

• density
• theory
• semiconductor
• hardness
• density functional theory
• ductility
• bulk modulus