Chemical tuning of magnetic anisotropy and correlations in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Ni</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>Fe</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:msub><mml:mi>PS</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math>
Seungyeol Lee, Jaena Park, Y. S. Choi, Kalaivanan Raju, Wei‐Tin Chen, Raman Sankar, Kwang‐Yong Choi
Abstract
We report the temperature and composition dependence of static magnetic susceptibility and Raman spectroscopic measurements on van der Waals antiferromagnets ${\mathrm{Ni}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x}{\mathrm{PS}}_{3}$. The end members ${\mathrm{NiPS}}_{3}$ and ${\mathrm{FePS}}_{3}$ feature $XY$- and Ising-like magnetism, respectively, enabling chemical tuning of magnetic anisotropy and spin correlations. ${\mathrm{Ni}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x}{\mathrm{PS}}_{3}$ shows a turnover from the $XY$ to Ising anisotropy through $x\ensuremath{\approx}0.1$. Although the $XY$ anisotropy is rapidly suppressed on introducing Fe content, two-magnon scattering evidences the slow repression of short-range magnetic correlations deep inside the Fe-rich side. Counterintuitively, the two-magnon signal undergoes less renormalization of its energy with increasing $x$ despite the larger spin number and enhanced classical magnetism. The disparate static and dynamic magnetic behaviors indicate the emergence of an exotic spin state in alloy van der Waals magnets.