Related papers: Modulated Martensite: Why it forms and why it defo…
Modulated phases occur in numerous functional materials like giant ferroelectrics and magnetic shape memory alloys. To understand the origin of these phases, we review and generalize the concept of adaptive martensite. As a starting point,…
Heusler alloys exhibiting magnetic and martensitic transitions enable applications like magnetocaloric refrigeration and actuation based on the magnetic shape memory effect. Their outstanding functional properties depend on low hysteresis…
Modulated martensites play an important role in magnetic shape memory alloys, because all functional properties are closely connected to the twin microstructure and the phase boundary. The nature of the modulated martensites is still…
We discuss modulation phasons as a possible source of unusual elastic behavior of five-layer modulated (10\,M) martensite of the Ni-Mn-Ga shape memory alloy. This material exhibits anomalous macroscopic shear compliance along specific…
Needle-like twins are observed experimentally within the transition layer at the martensite-twinned martensite interface. We utilize a phase-field approach to investigate this microstructure. Our goal is to simulate the morphology of the…
In a magnetic shape memory alloy system, we vary composition following phenomenological arguments to tune macroscopic properties. We achieve significantly higher shift in austenite to martensitic phase transition temperature with magnetic…
We present here results of temperature dependent high resolution synchrotron x-ray powder diffraction study of sequence of phase transitions in Ni2MnGa. Our results show that the incommensurate martensite phase results from the…
We use phase field simulations to study composites made of two different ferroelastics (e.g., two types of martensite). The deformation of one material due to a phase transformation can elastically affect the other constituent and induce it…
High mobility of twin boundaries in modulated martensites of Ni-Mn-Ga-based ferromagnetic shape memory alloys holds a promise for unique magnetomechanical applications. This feature has not been fully understood so far, and in particular it…
Shape memory alloys often show a complex hierarchical morphology in the martensitic state. To understand the formation of this twin-within-twins microstructure, we examine epitaxial Ni-Mn-Ga films as a model system. In-situ scanning…
Based on original investigations into the stages of nucleation and growth of martensite, a consideration has been given to dynamic models of formation of martensite plates with a fine structure of transformation twins, which are compatible…
Understanding the crystal structure of magnetic shape memory alloys is crucial for insights into their unique properties, such as the high mobility of twin boundaries and magnetic field functionality. The complex neutron diffraction…
7M orthorhombic modulated structure in the martensite phase of Ni1.8Pt0.2MnGa is reported by powder neutron diffraction study, which indicates that it is likely to exhibit magnetic field induced strain. The change in the unit cell volume is…
Ferroic materials enable a multitude of emerging applications, and optimum functional properties are achieved when ferromagnetic and ferroelectric properties are coupled to a first-order ferroelastic transition. In bulk materials, this…
The martensitic transformation is one of the most important phenomena in metals science due to its essential contribution to the strength of steels and most engineering alloys. Yet the basic, atomistic mechanisms leading to martensite…
Martensites are metastable phases, possessing a characteristic morphology, usually formed during a fast quench accross a structural transition. We attempt to understand these morphological features using a coarsegrained free energy…
When a crystalline solid such as iron is cooled across a structural transition, its final microstructure depends sensitively on the cooling rate. For instance, an adiabatic cooling across the transition results in an equilibrium `ferrite',…
We use the phase-field method to study the martensitic transformation at the nanoscale. For nanosystems such as nanowires and nanograins embedded in a stiff matrix, the geometric constraints and boundary conditions have an impact on…
The impact of shear deformation in $(1\,0\,1)[1\,0\,\bar{1}]$ system of non-modulated (NM) martensite in Ni$_2$MnGa ferromagnetic shape memory alloy is investigated by means of ab initio atomistic simulations. The shear system is associated…
Symmetry-lowering structural phase transitions result in multiple degenerate structures whose coexistence is determined by macroscopic strain compatibility. In quantum materials, these structural transformations often couple to electronic…