Nicolau Bom

Barocaloric materials have shown to be promising alternatives to the conventional vapor-compression refrigeration technologies. Nevertheless, barocaloric effect ({\sigma}b-CE) has not been extensively examined for many classes of materials up to now. Aiming at fulfilling this gap, this paper describes the development of a high-pressure experimental...

Barocaloric effects in vulcanized natural rubber (V-NR) has been investigated. Direct measurements of the temperature change ({\Delta}T) around room temperature (283-333 K) resulted in large values, above 10 K, for a pressure change of 173 MPa. A power law was proposed to fit {\Delta}T as function of the maximum pressure, showing to be suitable for...

The barocaloric effect is still an incipient scientific topic, but it has been attracting an increasing attention in the last years due to promising perspectives for application in alternative cooling devices. Here, we present giant values of barocaloric entropy change and temperature change induced by low pressure changes in the PDMS elastomer aro...

The conversion of monolayer graphene grown epitaxially on SiC(0001) into quasi-free standing bilayer graphene (QFSBG) can be achieved by decoupling the buffer layer (BL) from the substrate via an annealing step. We investigated the role of O-2 and H2O (possible agents of this process) by varying the annealing atmosphere and time. Raman spectroscopy...

H and O incorporation in single-layer graphene (SLG) transferred onto SiO2/Si substrates following annealing in water vapor (H2O) was investigated. The use of isotopically enriched water in conjunction with nuclear reaction analysis enabled us to specifically investigate the effect of water annealing, among other modification agents of graphene lik...

Solid-state cooling based on caloric effects is considered a viable alternative to replace the conventional vapor-compression refrigeration systems. Regarding barocaloric materials, recent results show that elastomers are promising candidates for cooling applications around room-temperature. In the present paper, we report supergiant barocaloric ef...

This is a comment on the review paper “Novel mechanocaloric materials for solid-state cooling applications”, published recently. The mechanocaloric effects have three specific categories: elastocaloric, barocaloric and torsiocaloric (also known as twistocaloric). Depending on the experiment using compressive stress, one may erroneously interpret th...

Management of discarded tires is a compelling environmental issue worldwide. Although there are several approaches developed to recycle waste tire rubbers, their application in solid-state cooling is still unexplored. Considering the high barocaloric potential verified for elastomers, the use of waste tire rubber (WTR) as a refrigerant in solid-sta...

Management of discarded tires is a compelling environmental issue worldwide. Although several approaches have been developed to recycle waste tire rubbers, their application in solid-state cooling is still unexplored. Considering the high barocaloric potential verified for elastomers, the use of waste tire rubber (WTR) as refrigerant in solid-state...

Elastomers have shown to be promising barocaloric materials, being suitable candidates for solid-state cooling devices. Moreover, this family of polymers presents additional advantages, such as their low cost and long fatigue life. In this context, we investigated the barocaloric effects in Nitrile Butadiene Rubber (NBR) in a large range around roo...

Elastomers have shown to be promising barocaloric materials, being suitable candidates for solid-state cooling devices. Moreover, this family of polymers presents additional advantages, such as their low cost and long fatigue life. In this context, we investigated the barocaloric effects in Nitrile Butadiene Rubber (NBR) in a large range around roo...

Solid-state cooling based on i-caloric effects is considered the most promising alternative to replace the conventional vapor-compression refrigeration systems. It is possible to define an i-caloric effect as a thermal response registered in a material upon the application of an external field, characterized by an adiabatic temperature change ({\De...

Solid-state cooling based on i-caloric effects is considered a viable alternative to replace the conventional vapor-compression refrigeration systems. Regarding barocaloric materials, recent results show that elastomers are promising candidates for cooling applications around room-temperature. In the present paper, we report supergiant barocaloric...

Solid-state cooling based on i-caloric effects has shown to be a promising alternative to the conventional refrigeration devices. Only very recently, the research on barocaloric materials is receiving a deal of attention due to the demonstration of giant barocaloric effects in shape-memory alloys. Regarding polymers, there is still a lack of litera...

Solid-state cooling based on i-caloric effects has shown to be a promising alternative to the conventional refrigeration devices. Only very recently, the research on barocaloric materials is receiving a deal of attention due to the demonstration of giant barocaloric effects in shape-memory alloys. Regarding polymers, there is still a lack of litera...

Barocaloric materials have shown to be promising alternatives to the conventional vapor-compression refrigeration technologies. Nevertheless, barocaloric effect (σb-CE) has not been extensively examined for many classes of materials up to now. Aiming at fulfilling this gap, the present paper describes the development of a high-pressure experimental...

The barocaloric effect is still an incipient scientific topic, but it has been attracting an increasing attention in the last years due to the promising perspectives for its application in alternative cooling devices. Here, we present giant values of barocaloric entropy change and temperature change induced by low pressures in PDMS elastomer around...

Barocaloric effect in vulcanized natural rubber (V-NR) has been investigated. Direct measurements of the temperature change ({\Delta}T) around room temperature (283-333 K) resulted in large values, above 10 K, for a pressure change of 173 MPa. A power law was proposed to fit {\Delta}T as function of the maximum pressure, showing to be suitable for...

Deuterium (D) incorporation in GeO2/Ge structures following D2 annealing was investigated. Higher D concentrations were obtained for GeO2/Ge samples in comparison to their SiO2/Si counterparts annealed in the same conditions. Oxygen vacancies produced during the annealing step in D2 constitute defect sites for D incorporation, analogous to defects...

Owing to its unique properties with respect to charge transport, graphene is one of the most promising candidates for future nanoelectronic devices. However, the processing and modification of graphene properties for technological purposes is still a challenge. In this context, gases adsorption in graphene is of central importance. It has been alre...

Al2O3 was deposited by pulsed DC reactive sputter on Ge(1 0 0) aiming at producing layers with reduced OH and H2O content in comparison with water-based atomic layer deposition. In this way, the intrinsic interaction of Al2O3 with Ge could be probed. Photoelectron spectroscopy showed evidence of a GeO2 interlayer in as-deposited samples. Thermal an...

Al2O3 films were deposited on Ge substrates by reactive sputtering. Resulting samples were submitted to different post-deposition annealings (PDAs) in order to probe composition modifications induced by such treatments. Nuclear reaction profiling (NRP) revealed that O incorporation depends on PDA temperature and on the employed atmosphere (water or...

Five-nanometer-thick Al2O3 films were deposited on Ge substrates by reactive sputtering and submitted to post-deposition annealings (PDAs) in argon, forming gas, oxygen, or water vapor at 350 or 500 degrees C for 30 min. Photoelectron spectroscopy evidenced that Ge was oxidized during the deposition process. Thermal annealing in argon or forming ga...

Experimental evidences of enhanced stability of Al2O3/SiC structures following thermal annealing are presented. 5- and 40-nm-thick Al2O3 films evaporated on the Si- and C-terminated faces of 4H-SiC were annealed up to 1000 °C in different atmospheres, leading to crystallization and densification of Al2O3, with an increase in the band gap. Exposure...