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.
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
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
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
Giant stress-impedance (GSI) sensor for diameter evaluation incylindrical elements
(Elsevier, 2018-01-01) Beato López, Juan Jesús; Vargas Silva, Gustavo Adolfo; Pérez de Landazábal Berganzo, José Ignacio; Gómez Polo, Cristina; Ingeniería; Ingeniaritza; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Gobierno de Navarra / Nafarroako Gobernua
In this work, a magnetoelastic sensor to detect the micrometer diameter variations of cylindrical elements is analyzed. A nearly zero magnetostrictive amorphous ribbon with nominal composition (Co₀.₉₃Fe₀․₀₇)₇₅Si₁₂․₅B₁₂․₅ was selected as sensor nucleus. The sensor, based on Giant Stress-Impedance (GSI), is attached (glued) along the external perimeter of the cylindrical element. Changes in the cylindrical diameter, DM, induce effective tensile stresses, S, on the ribbon, giving rise to sensitive changes in the high frequency impedance, Z. The sensor response is analyzed in terms of the relationship between the induced strains and the diameter variations, where the effect of geometrical factors (cylinder diameter and sample length) is taken into account. The results indicate that although the maximum GSI ratio depends on the pre-induced bending stresses associated to the cylindrical configuration, the sample length plays the dominant role in the sensor sensitivity. The proposed device enables to monitor the micrometric diameter variation in cylindrical elements, with a maximum strain gauge factor (GF≈-80) for low induced strains.
Embargo
Modified rule of mixtures and Halpin-Tsai models applied to PCL/NiMnInCo 4D printed composites. Internal stresses study during the martensitic transformation.
(Elsevier, 2025-05-26) Lambri, Fernando Daniel; Bonifacich, Federico Guillermo; Lambri, Osvaldo Agustín; Weidenfeller, B.; Recarte Callado, Vicente; Sánchez-Alarcos Gómez, Vicente; Pérez de Landazábal Berganzo, José Ignacio; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
4D printing enables the manufacturing of complex smart components in a wide variety of shapes. In devices based on 4D printed composite materials, the interaction between the active microparticles and the printable polymer matrix plays a critical role for the optimal functionality. Key parameters in these materials are the elastic misfit coefficient, which monitors internal stresses, and elastic energy transfer, which determines the ability to transfer strain from the microparticles to the surrounding matrix. In this work, the temperature-dependent shear modulus of PCL/Ni45Mn36.7In13.3Co5 4D printed composites is analysed using the modified rule of mixture (ROM) and Halpin-Tsai (HT) models. The molecular flow caused by the polymer chain movement under oscillatory mechanical stress at relatively elevated temperatures is examined and discussed using these models. Additionally, the effect of an external direct magnetic field on the shear modulus is also analysed. Finally, the internal stresses in the composite materials resulting from the martensitic transformation in the active microparticles are studied through a modified mean-field model based on the Eshelby's inclusion theory.
Embargo
Boosting Li-S batteries through the synergistic effect of recycled ferrites and external magnetic induction
(Elsevier, 2025-02-01) Bonilla, Álvaro; Jiménez Blasco, Uxua; Gómez-Cámer, Juan Luis; Garayo Urabayen, Eneko; Pérez de Landazábal Berganzo, José Ignacio; Caballero, Álvaro; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Gobierno de Navarra / Nafarroako Gobernua, PC003-04 3D-MAGNET
Despite being considered one of the most promising energy storage technologies, lithium-sulfur batteries (LSBs) are limited in terms of commercialization by the shuttle effect and slow reaction kinetics. In this work, we demonstrate for the first time that the use of recycled ferrite in conjunction with an external magnetic field generated by a permanent magnet can enhance the reaction kinetics and the adsorption of polysulfides (LiPSs), and hence the electrochemical stability. An in-depth kinetic study shows that under the effect of an external magnetic field, the electrode has lower polarization, a higher Li+ diffusion coefficient and a lower activation energy between electrochemical stages. The electrode also has a capacity retention up to 40 % higher and half the capacity loss per cycle at a high rate of 1C. At an ultra-high rate of 10C, the electrode has a capacity of 507 mAh g−1 after 150 cycles and an areal capacity of up to 3 mAh cm−2 at an ultra-high loading of 13 mg cm−2. In addition to the promising results observed in electrochemical terms, our approach is also more sustainable due to the use of a recycled electronic material obtained via dry milling, thereby avoiding the use of fossil carbons.
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
Effect of Cu substitution on the magnetic and magnetic induction heating response of CdFe₂O₄ spinel ferrite
(Elsevier, 2020) Ghasemi, R.; Echeverría Morrás, Jesús; Pérez de Landazábal Berganzo, José Ignacio; Beato López, Juan Jesús; Naseri, M.; Gómez Polo, Cristina; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias
In this work, a comparative study of the effect of Cu on the structural, magnetic and magnetic induction heating response in CdFe2O4 spinel is presented. The ceramic nanoparticles (Cu1−xCdxFe2O4; 0 ≤ x ≤ 1) were synthesized by co-precipitation from Cu(II), Cd(II) and Fe(III) salts. The samples, characterized by X-ray diffractometry, display the characteristic spinel cubic structure (space group Fm3m) where CdO is detected as main secondary phase (≈ 16% weight for x = 1). A high degree of nanoparticle agglomeration is inferred from the Transmission Electron Microscopy (TEM) images, as a consequence of the employed synthesis procedure. Regarding the magnetic properties, superparamagnetic behavior at room temperature can be disregarded according to the low field magnetization response (ZFC-FC curves). For 0.4 ≤ x ≤ 0.8 ratios, the samples display maximum values in the magnetic moment that should be correlated to the cation distribution between the octahedral and tetrahedral sites. Maximum magnetization values lead to an enhancement in the magnetic induction heating response characterized by highest heating temperatures under the action of an ac magnetic field. In particular, maximum SAR values are estimated for x = 0.8 as a combined effect of high magnetic moment, low dc coercive field (high susceptibility). Although these Cu-Cd ferrite nanoparticles display moderate SAR values (around 0.7 W/g), the control of the maximum heating temperatures through the cation distribution (composition) provides promising properties to be used as nanosized heating elements (i.e. hyperthermia agents).
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.