Dataset for research paper entitled Adaptive Phase or Variant Formation at the Austenite/Twinned Martensite Interface in Modulated Ni–Mn–Ga Martensite

The dataset contains the experimental result concerning in-situ synchrotron and SEM/EBSD measurements as a function of temperature. The list of files is listed below:

The dataset is composed of both the raw and processed data:

X-ray phase analysis - performed with a synchrotron radiation energy 87.1 KeV.

Origin file 1 - Diffraction experiments made on NiMnGa single crystals below and above Ms temperature

2D Diffraction pattern for 10M 10M’ Mt, and A structures.

TEM experiments - Microstructural observations were carried out by ThermoFisher Scientific TitanThemis Cs corrected 200 kV scanning /transmission electron microscope (S/TEM) equipped with SuperX EDX detector system. Thin foil for analysis was prepared by TEM observations were prepared with a TenuPol-5 double jet electropolisher using an electrolyte of nitric acid (70%) and methanol (30%) at -25 °C.

·      File 1 set of HRTEM images showing modulation boundaries

·      File 2 set of HRTEM images showing a/b boundaries

SEM/EBSD - FEI Quanta 3D FEG SEM equipped with a TSL system and a Murano heating stage. To analyze the lattice parameter changes, a crystallographic analysis of lattice metric (CALM) was used. This method does not need a standard for indexing or lattice constant determination. The lattice metric (lattice parameters) was derived through the reconstruction of the experimental EBSD pattern. In the first step, centers of Kikuchi band traces were detected from the EBSD diffraction pattern. Then, using information about the diffraction projection center, 20 to 100 independent reflectors were reconstructed in the reciprocal space. The final step involves a search for primitive lattice vectors which are fulfilling translational symmetry conditions for all reflectors. Reconstructed vectors are recomputed to the higher symmetry lattices with a relative error lower than 0.1%Thermogravimetric curves obtained for the decomposition of powder after synthesis at 500 rpm.

Origin file 2 Relation between a/c lattice parameters

Origin file 3 Relation between a/c lattice parameters

SEM/BSE pictures showing austenite twinned/martensite interface

Video 1 shows in-situ SEM/BSE with martensitic transformation and one planar austenite/twinned martensite interface during cooling

Video 2 shows set of Kikuchi pattern across Austenite martensite phase indicating elastic nature of the martensitic transformation