Data for Paper "Field-dependent anisotropic magnetic coupling in layered ferromagnetic Fe3-xGeTe2"

Single-crystal Fe3−xGeTe2 was synthesized by the self-flux technique. The crystal structure of Fe3−xGeTe2 was checked by x-ray diffraction (XRD), which was performed on a Rigaku-TTR3 x-ray diffractometer with high-intensity graphite monochromatized Cu Kα radiation. The chemical composition was carefully determined by energy dispersive x-ray (EDX) spectrometry, which gives that the vacancy of Fe is x ∼ 0.28. The angle-, temperature-, and field-dependent magnetization measurements were carried out by a Quantum Design vibrating sample magnetometer (SQUID-VSM). In particular, the initial isothermal magnetization with field applied along the c axis and within the ab plane was measured to obtain the magnetic entropy change. Before each measurement, the sample was warmed to room temperature. After being held at that temperature for 2 min, the sample was cooled to the target temperature under zero field to get the initial magnetizing curves. The magnetic field and temperature were relaxed before data collection, and a no-overshoot mode was employed to ensure a precise magnetic field.