Open Access
Influence of structural defects on the properties of metamagnetic shape memory alloys
(MDPI, 2020) Pérez de Landazábal Berganzo, José Ignacio; Sánchez-Alarcos Gómez, Vicente; Recarte Callado, Vicente; Lambri, Osvaldo Agustín; López García, Javier; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias
The production of µ-particles of Metamagnetic Shape Memory Alloys by crushing and subsequent ball milling process has been analyzed. The high energy involved in the milling process induces large internal stresses and high density of defects with a strong influence on the martensitic transformation; the interphase creation and its movement during the martensitic transformation produces frictional contributions to the entropy change (exothermic process) both during forward and reverse transformation. The frictional contribution increases with the milling time as a consequence of the interaction between defects and interphases. The influence of the frictional terms on the magnetocaloric effect has been evidenced. Besides, the presence of antiphase boundaries linked to superdislocations helps to understand the spin-glass behavior at low temperatures in martensite. Finally, the particles in the deformed state were introduced in a photosensitive polymer. The mechanical damping associated to the Martensitic Transformation (MT) of the particles is clearly distinguished in the produced composite, which could be interesting for the development of magnetically-tunable mechanical dampers.
Open Access
Steering the synthesis of Fe3O4 nanoparticles under sonication by using a fractional factorial design
(Elsevier, 2021) Echeverría Morrás, Jesús; Moriones Jiménez, Paula; Garrido Segovia, Julián José; Ugarte Martínez, María Dolores; Cervera Gabalda, Laura María; Garayo Urabayen, Eneko; Gómez Polo, Cristina; Pérez de Landazábal Berganzo, José Ignacio; Ciencias; Zientziak; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute for Advanced Materials and Mathematics - INAMAT2; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
Superparamagnetic iron oxide nanoparticles (MNPs) have the potential to act as heat sources in magnetic hyperthermia. The key parameter for this application is the specific absorption rate (SAR), which must be as large as possible in order to optimize the hyperthermia treatment. We applied a Plackett-Burman fractional factorial design to investigate the effect of total iron concentration, ammonia concentration, reaction temperature, sonication time and percentage of ethanol in the aqueous media on the properties of iron oxide MNPs. Characterization techniques included total iron content, Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, High Resolution Transmission Electron Microscopy, and Dynamic Magnetization. The reaction pathway in the coprecipitation reaction depended on the initial Fe concentration. Samples synthesized from 0.220 mol L−1 Fe yielded magnetite and metastable precipitates of iron oxyhydroxides. An initial solution made up of 0.110 mol L−1 total Fe and either 0.90 or 1.20 mol L−1 NH3(aq) led to the formation of magnetite nanoparticles. Sonication of the reaction media promoted a phase transformation of metastable oxyhydroxides to crystalline magnetite, the development of crystallinity, and the increase of specific absorption rate under dynamic magnetization.
Open Access
Magnetically tunable damping in composites for 4D printing
(Elsevier, 2021) Bonifacich, Federico Guillermo; Lambri, Osvaldo Agustín; Recarte Callado, Vicente; Sánchez-Alarcos Gómez, Vicente; Pérez de Landazábal Berganzo, José Ignacio; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Composite materials are being used in the design of new devices to produce more functional, cheap and on-demand products. In particular, 3D printing technology based on composites opens a huge field enabling the freedom of design and the ability to manufacture complex structures. In this context, the analysis of the functional properties of printable composites is of great importance. The work is focused on the analysis of the mechanical damping of a composite made with different concentrations of a Ni45Mn36.7In13.3Co5 metamagnetic shape memory alloy into an UV-curing polymer. The composites provide a bulk material containing very brittle metallic μ-particles that can be handled for technological applications. Damping and dynamic modulus of the composites were modified with small magnetic fields below 100 kA/m, proving that the damping capacity can be tuned by applying an external magnetic field. From the measurements, it has been also possible to determine the intrinsic damping and moduli of the alloy particles, which show the characteristic properties linked to the MT. These preliminary results allow proposing this composite material as a potential functional material to be used in the design of printable devices for magneto-mechanical damping applications.
Open Access
Outstanding role of the magnetic entropy in arrested austenite in an ordered Ni45Mn36.7In13.3Co5 metamagnetic shape memory alloy
(Elsevier, 2019) Pérez de Landazábal Berganzo, José Ignacio; Recarte Callado, Vicente; Sánchez-Alarcos Gómez, Vicente; Jiménez Ruiz, M.; Cesari, Eduard; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias
The relevance of the entropy and in particular the outstanding role of the magnetic contribution is analyzed in a non-equilibrium arrested austenite phase in a Ni 45 Mn 36.7 In 13.3 Co 5 metamagnetic shape memory alloy. The Debye and Bragg-Williams approximations have been used to analyze and quantify the vibrational and magnetic contributions respectively, to the total entropy change linked to the martensitic transformation. The sign on the entropy change associated to the forward austenite to martensite transformation is different depending on whether it occurs at low or at high temperature as a consequence of the different vibrational and magnetic contributions.
Open Access
Fe3O4-SiO2 mesoporous core/shell nanoparticles for magnetic field-induced ibuprofen-controlled release
(American Chemical Society, 2022-12-23) García Rodríguez, Lucía; Garayo Urabayen, Eneko; López Ortega, Alberto; Galarreta Rodríguez, Itziar; Cervera Gabalda, Laura María; Cruz Quesada, Guillermo; Cornejo Ibergallartu, Alfonso; Garrido Segovia, Julián José; Gómez Polo, Cristina; Pérez de Landazábal Berganzo, José Ignacio; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA2020; Gobierno de Navarra / Nafarroako Gobernua
Hybrid magnetic nanoparticles made up of an iron oxide, Fe3O4, core and a mesoporous SiO2 shell with high magnetization and a large surface area were proposed as an efficient drug delivery platform. The core/shell structure was synthesized by two seed-mediated growth steps combining solvothermal and sol—gel approaches and using organic molecules as a porous scaffolding template. The system presents a mean particle diameter of 30(5) nm (9 nm magnetic core diameter and 10 nm silica shell thickness) with superparamagnetic behavior, saturation magnetization of 32 emu/g, and a significant AC magnetic-field-induced heating response (SAR = 63 W/gFe3O4, measured at an amplitude of 400 Oe and a frequency of 307 kHz). Using ibuprofen as a model drug, the specific surface area (231 m2/g) of the porous structure exhibits a high molecule loading capacity (10 wt %), and controlled drug release efficiency (67%) can be achieved using the external AC magnetic field for short time periods (5 min), showing faster and higher drug desorption compared to that of similar stimulus-responsive iron oxide-based nanocarriers. In addition, it is demonstrated that the magnetic field-induced drug release shows higher efficiency compared to that of the sustained release at fixed temperatures (47 and 53% for 37 and 42 °C, respectively), considering that the maximum temperature reached during the exposure to the magnetic field is well below (31 °C). Therefore, it can be hypothesized that short periods of exposure to the oscillating field induce much greater heating within the nanoparticles than in the external solution.
Open Access
Experimental observation of vacancy-assisted martensitic transformation shift in Ni-Fe-Ga alloys
(American Physical Society, 2019) Unzueta, Iraultza; Alonso de Robador Lorente, Daniel; Cesari, Eduard; Sánchez-Alarcos Gómez, Vicente; Recarte Callado, Vicente; Pérez de Landazábal Berganzo, José Ignacio; García, José Ángel; Plazaola, Fernando; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias
Positron annihilation lifetime spectroscopy is used to experimentally demonstrate the direct relationship between vacancies and the shift of the martensitic transformation temperature in a Ni55Fel7Ga28 alloy. The evolution of vacancies assisting the ordering enables shifts of the martensitic transformation up to 50 K. Our results confirm the role that both vacancy concentration and different vacancy dynamics play in samples quenched from the L2(1) and B2 phases, which dictate the martensitic transformation temperature and its subsequent evolution. Finally, by electron-positron density functional calculations V-Ni is identified as the most probable vacancy present in Ni55Fe17Ga28. This work evidences the capability of vacancies for the fine-tuning of the martensitic transformation temperature, paving the way for defect engineering of multifunctional properties.
Open Access
Magnetic fabrics of weakly-deformed mudrocks from the Jaca-Pamplona basin (Pyrenees); new constrains on the sensitivity of magnetic fabrics and the tectonic evolution of the Southern Pyrenees
(Springer, 2025-03-03) Sierra-Campos, Pablo; Calvín, Pablo; Izquierdo-Llavall, Esther; Pérez de Landazábal Berganzo, José Ignacio; Montes, M.; Luzón, A.; Bellido, E.; Pueyo, E. L.; Larrasoaña, Juan Cruz; Ciencias; Zientziak
La anisotropía de la susceptibilidad magnética (ASM) es una técnica que se ha mostrado muy efciente en el estudio de la evolución tectónica de cinturones orogénicos. En rocas débilmente deformadas depositadas en contextos compresivos, la ASM viene marcada por la orientación preferente de flosilicatos paramagnéticos ocurrida durante la diagénesis inicial como respuesta al acortamiento paralelo a las capas (LPS). Estas fábricas asociadas al LPS pueden verse modifcadas con posterioridad como respuesta al cizallamiento en la cercanía de planos de cabalgamiento. En este trabajo se presenta el análisis de la ASM en dos secciones, Izaga y Berdún, que se sitúan en la cuenca de Jaca-Pamplona (Zona Surpirenaica) y registran la evolución tectonosedimentaria de la cuenca desde el Luteciense Superior al Priaboniense Medio. Las partes inferior y superior de la serie de Izaga muestran elipsoides triaxiales/oblatos y oblatos, respectivamente, que indican un decaimiento en la intensidad del LPS asociado a la actividad decreciente del lejano sistema de cabalgamientos de Larra. La sección de Berdún comienza con elipsoides oblatos, que cambian rápidamente a triaxiales y prolatos antes de volver a oblatos hacia la parte media y superior de la serie. Los elipsoides triaxiales y prolatos en la parte baja de la serie marcan, junto con el desarrollo de una guirnalda incipiente entre los ejes mínimos e intermedios de la ASM, el efecto adicional de un cizallamiento que relacionamos con un cabalgamiento no detectado anteriormente y cuya presencia ha sido corroborada por análisis estructural. Aunque el resto de la serie de Berdún refeja el efecto del LPS, no ha sido posible determinar si éste viene condicionado por una estructura cercana o lejana. Los elipsoides prolatos reaparecen en el techo de la serie, circunstancia que relacionamos con un LPS más intenso asociado a la actividad tectónica que condicionó continentalización de la cuenca.
Open Access
Evolution of magnetic response as a function of annealing temperature in Fe-based alloys
(Rede Latino-Americana de Materiais, 2018) Gargicevich, Damián; Bonifacich, Federico Guillermo; Lambri, Osvaldo Agustín; Pérez de Landazábal Berganzo, José Ignacio; Recarte Callado, Vicente; Fisika; Institute for Advanced Materials and Mathematics - INAMAT2; Física; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The magnetic response, coercive force and magnetic induction, in Fe-10at.% Si, Fe-6at.% Al-9at.% Si and Fe-4at.% Al-8at.% Ge alloys as a function of the annealing temperature was determined and correlated to the microstructural state. The microstructural characterization was made through differential thermal analysis, mechanical spectroscopy and neutron thermodiffraction studies. It has been determined that the increase in the order degree and the decrease in the mobility of structural defects lead to a deterioration of the magnetic quality of the alloys above detailed.
Open Access
Correlation between particle size and magnetic properties in soft-milled Ni45Co5Mn34In16 powders
(Elsevier, 2021) Khanna, Deepali; Sánchez-Alarcos Gómez, Vicente; Recarte Callado, Vicente; Pérez de Landazábal Berganzo, José Ignacio; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Gobierno de Navarra / Nafarroako Gobernua, PC017-018 AMELEC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The effect of microstructural defects induced by mechanical milling has been studied in a Ni–Mn–In–Co metamagnetic shape memory alloy. The martensitic transformation and Curie temperatures do not change with grinding, thus pointing out to a null variation of long range atomic order as a consequence of the deformation. Nevertheless, the enthalpy change of the martensitic transformation highly decreases. This, and the large thermal stabilization of the martensite (with shifts on the temperature of the first reverse martensitic transformation up to 60 K), indicate the presence of a huge amount of internal stresses and microstructural defects in the obtained micro-particles. The presence of such defects considerably affects the saturation magnetization in austenite whereas almost no effect is observed in martensite. The magnetocaloric effect has been evaluated in samples with three different particle sizes. In spite of the MCE value is lower than in the bulk, the broader temperature range for the martensitic transformation in the powders makes the relative cooling power be comparable to that in the bulk. The as-milled micro-particles can be then considered as good preliminary candidates for magnetic refrigeration applications at the microscale.
Open Access
Magnetic behavior in commercial iron-silicon alloys controlled by the dislocation dynamics at temperatures below 420 K
(Elsevier, 2021) Lambri, Osvaldo Agustín; Weidenfeller, B.; Bonifacich, Federico Guillermo; Pérez de Landazábal Berganzo, José Ignacio; Cuello, G.J.; Weidenfeller, L.; Recarte Callado, Vicente; Zelada, Griselda Irene; Riehemann, W.; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
A decrease of the temperature dependent coercive forces up to around 370 K is discovered in iron silicon alloys, both in quenched samples and in samples which were previously thermally treated to achieve the highest magnetic quality. Alloys of composition Fe-6 wt.% Si and Fe-3 wt.% Si are studied. This reduction in the coercive force is controlled by an increase in the mobility of the domain walls due to the increase in the dislocation's mobility enhanced by the movement of vacancies. It is worthwhile to mention that this reduction in coercive force is only present at these slightly elevated temperatures which are markedly smaller than the usual annealing temperatures for heat treatment of iron silicon alloys while it disappears again at room temperature. Neutron thermodiffraction, magnetic hysteresis loops tracer and mechanical spectroscopy are used as experimental techniques.