From Scarcity to Quality: Tailored Laser-Diode Floating-Zone Growth of Small-Mass Isotope-Enriched 160GdRu2Ge2 Skyrmion Crystals

Abstract

Access to sizable, high-quality single crystals plays a seminal role in advancing the frontier of materials research, with both fundamental and technological applications. Centrosymmetric Gd-based magnetic metals represent a promising platform for realizing topologically nontrivial magnetic states, such as skyrmions, with excellent potential for high-density, low-power spintronics. Despite the availability of numerous conventional crystal growth techniques for these materials, methods that can produce scarce, isotopically enriched crystals remain limited. Here, we demonstrate tailored laser-diode floating-zone growth that enables the preparation of centimeter-sized, high-quality ¹⁶⁰GdRu₂Ge₂ single crystals using a fraction (∼10%) of the starting material required by traditional methods. Results from single-crystal X-ray diffraction, back-reflection Laue X-ray diffraction, SEM, and elemental analysis reveal phase-pure, single-crystal grains. Magnetization measurements for ¹⁶⁰GdRu₂Ge₂ confirm skyrmion phase transitions. Our work establishes a feasible pathway for the successful growth and processing of high-value materials with scarce isotopes or limited sample availability, furthering insights into physical phenomena through spectroscopy and other characterization techniques while broadening opportunities for technological integration.