These datasets were used for fluctuation electron microscopy (FEM) analysis of amorphous Tb17Co83. The Tb17Co83 is 30 nm thick. The deposited Ta is sandwiched between two layers of amorphous 10 nm-thick SiNx. Data are also provided for SiNx deposited on SiNx. Samples include: (1) Tb17Co83 deposited at 20oC, (2) Tb17Co83 deposited at 200oC, (3) Tb17Co83 deposited at 300oC, (4) Tb17Co83 deposited at 20oC and annealed at 200oC, and (5) Tb17Co83 deposited at 20oC and annealed at 300oC. FEM patterns were collected in a FEI TitanX operated at 200 kV with a convergence angle of 0.51 mrad and a camera length of 300 mm. Samples (1) Tb17Co83 deposited at 20oC and (3) Tb17Co83 deposited at 300oC were tilted between 0o and 40o in 5o increments. The tilted FEM data is also included. File types .dm4 (Gatan DigitalMicrograph) files are provided with the raw scanning nanodiffraction data for each sample. Each sample has multiple associated .dm4 files because measurements were repeated for statistical purposes. Data processing For the steps involved in FEM data processing, please visit: https://github.com/ScottLabUCB/FEM File name format Using "gRTa200_t00_200kV_cl300_ca0p51_exp0p3_spot9_ss5nm_04.dm4" as an example, the naming format is: "sample descriptor _ tilt angle _ TEM voltage_camera length [mm] _ convergence angle [mrad] _exposure [sec] _spot size _ step size between probe positions [nm]_ data set number.dm4" Data are from Tb17Co83 capped with SiNx unless only "SiN" is stated in the descriptor, in which case the data are from SiNx. For the tilted data, the naming format is: "sample descriptor _ tilt angle _ spot size _ exposure [sec] convergence angle [mrad]_ bin factor _camera length _ TEM voltage _ data set number.dm4" For all data, the step size is 5 nm, the spot size is 9, the exposure is 0.3 seconds, the convergence angle is 0.51 mrad, the camera length in 300 mm, and the TEM extraction voltage is 200 kV.