## 2 Materials and Methods
### Fundamental Analysis of SC Ni-Mn-Ga Alloys  
2.5.1. Thermal Analysis  
Thermal analysis was carried out for the determination of the phase transformation temperatures by using a differential scanning calorimeter (DSC; DSC-60 Plus, Shimadzu, Kyoto, Japan). Flakes of the homogenized SC Ni-Mn-Ga alloys with a certain weight were used to carry out the thermal analysis. The temperature was scanned from 273 K to 373 K with a scan rate of 10 K min\({}^{-1}\) under a high-purity Ar atmosphere to avoid an oxidation reaction. A standard Al\({}_{2}\)O\({}_{3}\) powder was used as a reference material. Three cycles were scanned, with the last cycle used for the analysis of the phase transformation temperatures. 2.5.2. X-ray Diffraction Measurements  
\(\theta\)-2\(\theta\) X-ray diffraction measurements were conducted at RT for phase identification by using an X-ray diffractometer (XRD; X'Pert PRO, PANalytical, Malvern, UK). The SC Ni-Mn-Ga particles, which were subjected to the heat treatment at 1073 K for 3.6 ks, were used for the X-ray diffraction measurements. CuK\({}_{\alpha}\) radiation with a tube voltage of 45 kV and tube current of 40 mA, respectively, was utilized as the X-ray source, where the \(\lambda\) was 0.15405 nm. The scan range was 2\(\theta\) = 20-120\({}^{\circ}\) and the scan rate was 2.2\({}^{\circ}\) min\({}^{-1}\). A standard Si plate was used as a reference material for the correction of the external error. 2.5.3. Microstructure Observations  
Optical microscopy (VHX-100F, KEYENCE Co., Ltd., Osaka, Japan) was used for the observations of the microstructures of the SC ingot, which was fabricated via the FZ method as described in Section 2.3.3. Before the microstructure observations, SC Ni-Mn-Ga plates were sliced down from the ingot by using an EDM as described in Section 2.3.3. The SC Ni-Mn-Ga plates were then subjected to grinding and polishing processes. Grinding was carried out by using SiC papers from #1000 to #4000, followed by a polishing process with Al\({}_{2}\)O\({}_{3}\) suspensions down to 0.5 um to obtain a fine surface finish. During the grinding and polishing, the specimens were maintained at a temperature higher than the reverse martensitic transformation finish temperature (\(A_{\ell}\)) by controlling their environmental temperature to keep the specimen in the austenite state. Subsequently, the specimens were quenched into iced water (i.e., 273 K) to trigger the martensitic transformation (MT). The OM observations were conducted at RT. More details concerning the OM observations are described in the following Section 3. 2.5.4. Crystallographic Direction Identification  
The crystallographic directions of the specimens were confirmed by using X-ray diffraction pole figure analysis (Ultima IV multipurpose X-ray diffraction system, Rigaku Co., Ltd., Tokyo, Japan) at RT. Similar to those described in Section 2.5.2, CuK\({}_{\alpha}\) was used as the X-ray source while the tube voltage and tube current were 40 kV and 40 mA, respectively. The 2\(\theta\) = 44.1\({}^{\circ}\), 62.5\({}^{\circ}\), and 66.4\({}^{\circ}\), which were selected for the pole figure analysis corresponding to (202), (400), and (004), respectively. The azimuthal rotation angle (\(\psi\)) was from 0\({}^{\circ}\) to 360\({}^{\circ}\) with a rotation rate of 120\({}^{\circ}\) min\({}^{-1}\) and 5\({}^{\circ}\) step\({}^{-1}\), while the tilted angle (\(\varphi\)) was from 0\({}^{\circ}\) to 75\({}^{\circ}\) with a titling rate of 5\({}^{\circ}\) step\({}^{-1}\). 2.5.5. Mechanical Property Evaluations  
Compression tests were conducted on the SC Ni-Mn-Ga cubes, which were prepared as described in Section 2.3.3, for the evaluation of their mechanical properties. The compression tests were carried out by using a universal test machine (Shimadzu Autograph AG-IS 1 kN, Shimadzu Co., Ltd., Kyoto, Japan). The settings of the compression tests are shown in Figure S1 in the Supplementary Materials.