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.

采用自熔剂法合成了单晶Fe₃₋ₓGeTe₂。通过X射线衍射（X-ray Diffraction，XRD）对其晶体结构进行了表征，测试使用配备高强度石墨单色化Cu Kα辐射的理学（Rigaku）TTR3型X射线衍射仪完成。采用能量色散X射线光谱法（Energy Dispersive X-ray Spectrometry，EDX）对样品的化学成分进行了精准测定，结果表明铁空位x≈0.28。通过量子设计（Quantum Design）的振动样品磁强计（SQUID-VSM）完成了角度、温度及磁场依赖的磁化强度测量。为获取磁熵变，特别测试了磁场沿c轴及ab平面内的初始等温磁化曲线。每次测量前，均将样品升温至室温并保温2分钟，随后于零场条件下冷却至目标温度，以获得初始磁化曲线。数据采集前，需对磁场与温度进行弛豫处理，并采用无过冲模式以确保磁场精度。