Magnetic field-driven bionanomanipulation continues to be a challenging task because the force applied by current magnetic nanoparticles and nanoactuators is effectively limited to femto and pico Newtons at the proper field and gradient scales. Therefore, of particular interest is search for the new functional materials and new effects that provide a breakthrough opportunity for the influence of a remotely controlled magnetic field on a nano and micro Newton scale on living biological objects, such as bacteria, viruses, individual cells, etc. This work includes deep study of the structure, physical and multifunctional properties of a new family of Heusler Ni-Mn-In-V alloys demonstrating the magnetic shape memory effect responsible for actuation, shape change and the production of mechanical work on objects such as viruses and bacteria in a constant temperature environment. The possibilities of capturing, storing, processing of bionanoobjects are discussed.

In this work, a measuring system was developed according to the scheme of an AC bridge, with the help of which a constant voltage was applied to polymer-dispersed liquid-crystal films doped with silicon dioxide nanoparticles. For these cells with different content of silicon dioxide nanoparticles, capacitance-voltage measurements were carried out at different frequencies of the alternating voltage generator. For these cells, a memory effect was found, which manifests itself in the hysteresis behavior of the capacitance of these cells. The largest hysteresis area and the largest shift of the cell capacitance in the absence of an external field are observed at 10 kHz. In the entire region under study, with a minimum at a frequency of 10 kHz, the perpendicular component of the permittivity has a pronounced dispersion. It has been established that the content of silicon dioxide nanoparticles affects the permittivity of a polymer-dispersed liquid-crystal cell. The data obtained can be used in the development of energy-independent nanostructured data storage systems.

The functionalities of Ni–Ti alloys subjected to different deformation treatments are studied. A critical stress corresponding to the onset of degradation of the functional properties were determined; it was found that this stress is about twice as low as the yield stress. The efficiency coefficients of virtual thermodynamic machines with a working body made of the investigated materials were calculated and compared with the efficiency of a Carnot engine based on the same materials; the ideality factor has been calculated under the condition of actuating at stresses no higher than critical ones. It has been established that, at the single actuation, the highest ideality factor (9.7%) is characteristic of a material consisting of bars 20 to 5 mm in diameter obtained by warm forging at 350°C. It has been determined that, at discontinuous operation under stresses lower than the critical ones by a factor of 1.2, the ideality factor is 7.4–7.7% for alloys subjected to hot forging or equal channel angular pressing combined with warm forging.

Samples of ferroelectric functional materials based on lead zirconate titanate with the chemical formula PbTiO3-PbZrO3-PbNb2/3Zn1/3O3-PbNb2/3Mg1/3O3 and triglycine sulfate (NH2CH2COOH)3•H2SO4 were manufactured and characterized. The dielectric spectroscopy and differential scanning calorimetry confirmed the presence of phase transitions in them, and the characteristic transition temperatures were determined. Thermomechanical analysis method has been used to study thermally induced deformations in them, near phase transitions. The shape memory effect (SME) and electrocaloric effect in macro samples were studied. Methods of studying the SME on the microscale of sample sizes have been worked out. The process of formation of microstructures in these materials in the form of «micropillars» («micropillars») by selective ion etching with a focused ion beam is investigated. The process of deformation of «micro-pillars» with a diameter from 120 nm to 1 micron from ferroelectric materials using a microneedle mounted on a Kleidiek nanomanipulator in the vacuum chamber of a two-beam scanning microscope CrossBeam 1540 EsB has been studied.

A test machine has been designed for studying the thermomechanical properties of shape-memory-alloy microwires in a temperature range from −190 to +270°C, under mechanical stresses as high as 2000 MPa, and with deformations of up to 50%. The operation of the test machine is based on the method of sample stretching at a variable temperature and a constant load. The elongation of the sample is measured by an optical displacement sensor. The machine was tested on microwires made from the well-known Ni49.8Ti50.2 alloy with the shape memory effect. Using the machine, it is possible to investigate the functional properties of microwire samples with a shape memory effect, which are promising for applications in microsystem engineering, nanotechnology, and medical technology.

The Heusler alloys demonstrate magnetically induced strain and magnetocaloric properties, but the mechanical properties are poor. Therefore, in this work, the influence of thermomechanical treatment on the properties of Ni-Mn-Ga-Si Heusler alloys is considered. The effect of multi-axial isothermal forging on functional properties of the Ni2.30Mn0.73Ga0.90Si0.07 alloy at 973 K and true strain (e) of 3.9 is presented. It is shown that a unique two-phase microstructure is formed as a result of forging. The large grains in the size range of 100–200 µm are surrounded by a fine-grained structure. The study of the thermomechanical properties by the three-point bend test has shown that the alloy demonstrates a single-stage reversible deformation of 3.1% at a constant stress of 860 MPa as compared to the same alloy in the as-cast condition which shows 2% at 380 MPa. The specimen demonstrates a reversible deformation of 5% without any degradation during thermal cycling (with a base of up to 4000 thermal cycles) under a stress of 550 MPa and up to 5% with degradation occurring at 700 thermal cycles under a stress of 650 MPa. Thus, forging makes it possible to obtain a material with higher operational properties and greater resistance to fracture during multiple cycles of martensitic transformation. In this case, it is possible to obtain anisotropy of properties equal or close to that of the specimen in the as-cast state.

The thermomechanical properties of shape memory alloy Ni50Ti50 are studied after equal channel angular extrusion, torsion at a pressure of 6 GPa with 0.5 and 2 turns, and subsequent heat treatment (quenching or annealing). Parameters of the thermoelastic phase transformation of specimens in different conditions are determined. X-ray diffraction analysis is performed. It is shown that an increase in the degree of the high-pressure torsional deformation to two turns increases the degree of specimen structure amorphization and critical stresses to 3000 MPa, while deformation up to half a turn makes it possible to increase reversible bending strain to 16% at stresses up to 1210 MPa.

The thermoelastic properties and the elastocaloric effect (ECE) were studied in rapidly quenched ribbons of the Ti2NiCu alloy samples in amorphous and crystalline states under periodic mechanical tension with a frequency of up to 50 Hz. In the amorphous samples, elastic behavior is observed, described by Hooke’s law, with a high coefficient of thermal expansion α = 1.7 × 10−4 K−1. Polycrystalline ribbons of the Ti2NiCu alloy have the classical shape memory effect (SME), the temperatures of the forward and reverse thermoelastic martensitic transitions being Ms = 345 K, Mf = 325 K, As = 332 K, and Af = 347 K and the coefficient of the dependence of the transition temperature on mechanical stress being β = 0.12 K/MPa. The experimentally measured value of the adiabatic temperature change under the action of mechanical stress (ECE) in the amorphous state of the alloy at room temperature (Tr = 300 K) was ΔT = −2 K, with a relative elongation of ε = 1.5% and a mechanical stress of σ = 243 MPa. For crystalline samples of Ti2NiCu alloy ribbons, the ECE is maximum near the completion temperature of the reverse thermoelastic martensitic transformation Af, and its value was 21 K and 7 K under cyclic mechanical loads of 300 and 100 MPa, respectively. It is shown that the ECE value does not depend on the frequency of external action in the range from 0 to 50 Hz. The specific power of the rapidly quenched ribbon was evaluated as a converter of thermal energy at an external mechanical stress of 100 MPa; its value was 175 W/g at a frequency of 50 Hz. The thermodynamic model based on the Landau theory of phase transitions well explains the properties of both amorphous ribbons (reverse ECE) and alloy ribbons with EPF (direct ECE).

The results of investigation of functional characteristics of the Mn2NiGa Heusler alloy prepared by argon-arc melting are presented. Its electric resistance, magnetization, magnetocaloric and shape memory effects were studied using direct experimental techniques in a wide temperature range 100–400 K. The inverse magnetocaloric effect, which does not reach saturation in pulsed magnetic fields up to 50 T, was observed in both martensite and austenite phases. The value of reversible deformation in the alloy was as high as 0.35% under bending mechanical loads up to 247 MPa.

The work presents the investigations of the functional properties of the Heusler alloy Mn2NiGa, made by argon arc melting. The direct experimental methods were used to study: electrical resistance, magnetization, magnetocaloric effect, and shape memory effect in the wide temperature range of 100–400 K. The inverse magnetocaloric effect was found in both the martensitic and austenitic phases, which did not experience saturation in pulsed magnetic field up to 50 T. The values of reversible deformation in the alloy up to 0.35% were obtained with bending mechanical stress up to 247 MPa.

We have performed comparative analysis of functional properties and functional fatigue of alloys of the Ni–Mn–Ga system in the initial molded state and the Ni–Ti system in the initial hot-forged state without thermal treatment. It is shown that the Ni 2 MnGa alloy in the molded state is preferable for low-loaded actuating elements (up to 100 MPa) and low recoverable strains (up to 1.5%) in the temperature range from –85 to –75°C; the Ni–Ti system alloy in the hot-forged state should be used for high-loaded actuating elements (up to 500 MPa) and high recoverable strains (up to 8.5%) in the temperature range from –40 to 40°C.

A comparative study of the functional properties and functional fatigue of Ni-Mn-Ga alloys in the initial cast state and Ni-Ti alloys in the initial hot-forged state without heat treatment was carried out. Measurements were carried out using experimental technique of three-point bending of samples in the form of plates of ~ 0.7 mm x 10 mm x 1.5 mm. It is shown that Ni2MnGa alloy in the cast state is preferably used for lightly loaded actuators (up to 100 MPa) and reversible deformations (up to 1.5%) in the temperature range from -85 C to -75 C; Ni-Ti system alloy in hot-forged state is recommended for highly loaded actuators (up to 500 MPa) , high reversible deformations (up to 8.5%) in the temperature range from -40 C to 40 C.

Functional characteristics of bar semiproducts from shape memory NiTi alloys obtained by equal channel angular pressing, worm forging, and their combination are determined. The functional characteristics are measured and the phase transitions are studied under the conditions of three-point bending and thermocycling at a constant load. It is shown that the bar specimens subjected to warm forging at 350°C and to a combination of equal channel angular pressing at 450°C and warm forging possess the best level of functional properties.

ТЕРМОМЕХАНИЧЕСКИЕ СВОЙСТВА МИКРОПРОВОЛОК ИЗ СПЛАВА Ni 49,9 Ti 50,1 , ИЗГОТОВЛЕННЫХ ИЗ ПРУТКОВ, ПРОШЕДШИХ ТЕПЛУЮ КОВКУ И КОМБИНАЦИЮ РКУП И ТЕПЛОЙ КОВКИ В. С

An experimental test machine for studying of the thermomechanical properties of shape-memory alloys in the temperature range from −130 to +300°C under mechanical stresses of up to 2000 MPa and the maximum bending deformation of a sample of up to 20% is described. The principle of operation of the test machine is based on three-point bending of a sample at a variable temperature and a constant load. The deflection of the sample is measured by an optical displacement transducer, which determines the high accuracy and reliability of the results. The apparatus was tested using samples of the Ni49.8Ti50.2 shape-memory alloy.

The ingot of Fe40.71Ni27.33Co17.13Al12.05Ta2.73B0.05 alloy was produced by arc melting technique followed by heat treatment. The alloy ingot was cut by electro-discharge machining and was further subjected to rolling. The microstructure of surface, thermomechanical and magnetic properties were studied. The alloy exhibits superelasticity at temperature lower than 330 K. The hysteretic behavior of magnetization was observed. These properties can be explained by combination of states of the spin- and strain-glasses.