Microwave-Assisted Synthesis of the New Solid-Solution (V1-x Cr x )2GaC (0 ≤ x ≤ 1), a Pauli Paramagnet Almost Matching the Stoner Criterion for x=0.80

MAX phases that exhibit long-range magnetic order inthe bulk arestill very hard to synthesize. Chromium and manganese are the cutoffelements when transitioning through the 3dmetals that still form stablefull and doped MAX phases, respectively. An iron-based (on the M-site) bulk MAX phase does not exist. Therefore, otherstrategies to induce long-range magnetic ordering in bulk MAX phasesare necessary to open the path to new functional materials. Here,we demonstrate the nonconventional synthesis of a hitherto unknownMAX phase solid-solution (V1-x Cr x )(2)GaC by microwave heating. Thefull series with 0 < x < 1 (x = 0.20, 0.40, 0.50, 0.60, 0.80) forms almost single phase with minimaldifferences in their morphology. Their magnetic properties, however,differ rather significantly, with a maximum susceptibility around x = 0.80. Both the experimental and theoretical/ab initiomagnetic analysis confirm that the solid-solution (V1-x Cr x )(2)GaC isan itinerant Pauli paramagnet that almost fulfills the Stoner criterionfor ferromagnetic order (for compositions with x around0.80). This is a powerful insight into how chemical composition coupleswith electronic structure and the resulting bulk magnetic propertiesbecause it provides crucial guidelines to produce long-range orderedmagnetic MAX phases.

Automated summary

By microwave heating, we have successfully synthesized a previously unknown MAX phase solid-solution (V1-x Cr x )(2)GaC, which exhibits a crucial coupling between chemical composition and electronic structure, providing important guidelines for the synthesis of long-range ordered magnetic MAX phases.