Strain-gradient and curvature-induced changes in domain morphology of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>BaTi</mml:mi> <mml:msub> <mml:mi mathvariant="normal">O</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:m

We investigate the impact of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:mrow> <a:mi mathvariant="normal">O</a:mi> <a:msup> <a:mrow> <a:mi mathvariant="normal">H</a:mi> </a:mrow> <a:mo>−</a:mo> </a:msup> </a:mrow> </a:math> ions incorporation on the lattice strain and spontaneous polarization of <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"> <d:mrow> <d:mi>BaTi</d:mi> <d:msub> <d:mi mathvariant="normal">O</d:mi> <d:mn>3</d:mn> </d:msub> </d:mrow> </d:math> nanorods synthesized under different conditions. It was confirmed that the lattice strain depends directly on Ba supersaturation, with higher supersaturation leading to an increase in the lattice strain. However, it was shown that crystal growth and observed lattice distortion are not primarily influenced by external strain; rather, <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"> <f:mrow> <f:mi mathvariant="normal">O</f:mi> <f:msup> <f:mrow> <f:mi mathvariant="normal">H</f:mi> </f:mrow> <f:mo>−</f:mo> </f:msup> </f:mrow> </f:math> ions incorporation plays a key role in generating internal chemical strains and driving these processes. By using the less reactive <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"> <i:mrow> <i:mi>Ti</i:mi> <i:msub> <i:mi mathvariant="normal">O</i:mi> <i:mn>2</i:mn> </i:msub> </i:mrow> </i:math> precursor instead of <k:math xmlns:k="http://www.w3.org/1998/Math/MathML"> <k:mrow> <k:mi>TiOC</k:mi> <k:msub> <k:mi mathvariant="normal">l</k:mi> <k:mn>2</k:mn> </k:msub> </k:mrow> </k:math> and controlling Ba supersaturation, the slower nucleation rate enables more effective regulation of <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mrow> <m:mi mathvariant="normal">O</m:mi> <m:msup> <m:mrow> <m:mi mathvariant="normal">H</m:mi> </m:mrow> <m:mo>−</m:mo> </m:msup> </m:mrow> </m:math> ions incorporation and crystal growth. This in turn effects both particle size and lattice distortion, leading to <p:math xmlns:p="http://www.w3.org/1998/Math/MathML"> <p:mi>c</p:mi> <p:mo>/</p:mo> <p:mi>a</p:mi> </p:math> ratio of 1.013–1.014. The incorporation of <q:math xmlns:q="http://www.w3.org/1998/Math/MathML"> <q:mrow> <q:mi mathvariant="normal">O</q:mi> <q:msup> <q:mrow> <q:mi mathvariant="normal">H</q:mi> </q:mrow> <q:mo>−</q:mo> </q:msup> </q:mrow> </q:math> ions induces lattice elongation along the <t:math xmlns:t="http://www.w3.org/1998/Math/MathML"> <t:mi>c</t:mi> </t:math> axis, contributing to anisotropic growth, increasing of the rod diameter and their growth-induced bending. However, the possibility of the curvature-induced changes in domain morphology of <u:math xmlns:u="http://www.w3.org/1998/Math/MathML"> <u:mrow> <u:mi>BaTi</u:mi> <u:msub> <u:mi mathvariant="normal">O</u:mi> <u:mn>3</u:mn> </u:msub> </u:mrow> </u:math> nanorods remains almost unexplored. To study the possibility, we perform analytical calculations and finite element modeling, which provide insights into the curvature-induced changes in the strain-gradient, polarization distribution, and domain morphology in <w:math xmlns:w="http://www.w3.org/1998/Math/MathML"> <w:mrow> <w:mi>BaTi</w:mi> <w:msub> <w:mi mathvariant="normal">O</w:mi> <w:mn>3</w:mn> </w:msub> </w:mrow> </w:math> nanorods. Theoretical results reveal the appearance of the domain stripes in <y:math xmlns:y="http://www.w3.org/1998/Math/MathML"> <y:mrow> <y:mi>BaTi</y:mi> <y:msub> <y:mi mathvariant="normal">O</y:mi> <y:mn>3</y:mn> </y:msub> </y:mrow> </y:math> nanorod when the curvature exceeds a critical angle. The physical origin of the domain stripes emergence is the tendency to minimize the elastic energy of the nanorod by the domain splitting. These findings suggest that <ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML"> <ab:mrow> <ab:mi>BaTi</ab:mi> <ab:msub> <ab:mi mathvariant="normal">O</ab:mi> <ab:mn>3</ab:mn> </ab:msub> </ab:mrow> </ab:math> nanorods, with curvature-controllable amount of domain stripes, could serve as flexible race-track memory elements for flexotronics and domain-wall electronics. Overall, this work enhances the understanding of how the shape anisotropy, lattice strains, and strain gradients influence the domain morphology of ferroelectric nanorods, offering a pathway for tuning properties of the nanorods for advanced applications in nanoelectronics.