Structural and magnetic properties of epitaxial M n 3 Ga thin films

We report on the synthesis and characterization of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:mrow> <a:mi mathvariant="normal">M</a:mi> <a:msub> <a:mi mathvariant="normal">n</a:mi> <a:mn>3</a:mn> </a:msub> <a:mi>Ga</a:mi> </a:mrow> </a:math> thin films with controlled phase and orientation using DC magnetron sputtering. High-quality Mn-deficient hexagonal <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"> <d:mrow> <d:mi mathvariant="normal">M</d:mi> <d:msub> <d:mi mathvariant="normal">n</d:mi> <d:mn>3</d:mn> </d:msub> <d:mi>Ga</d:mi> </d:mrow> </d:math> films with C-plane and M-plane orientations were achieved on various single-crystal substrates, and their structural properties were systematically investigated by x-ray diffraction. Magnetization, Hall effect, and neutron diffraction measurements confirm the formation of antiferromagnetic order below <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"> <g:mrow> <g:msub> <g:mi>T</g:mi> <g:mi mathvariant="normal">N</g:mi> </g:msub> <g:mo>=</g:mo> <g:mn>460</g:mn> <g:mtext>–</g:mtext> <g:mn>470</g:mn> </g:mrow> </g:math> K and reveal its characteristic magnetic behavior. A sizable anomalous Hall effect is observed coexistent with weak net magnetization, consistent with the 120° noncollinear spin structure. The ability to tune both the crystal phase (hexagonal vs tetragonal) and orientation through composition and thermal treatment provides a platform for exploring the intrinsic magnetic and topological properties of <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"> <i:mrow> <i:mi mathvariant="normal">M</i:mi> <i:msub> <i:mi mathvariant="normal">n</i:mi> <i:mn>3</i:mn> </i:msub> <i:mi>Ga</i:mi> </i:mrow> </i:math> , with promising implications for antiferromagnetic spintronic applications.