The Curie temperature dependence on preparation conditions for Gd thin films

On the Growth and Physical-chemical Characterization of Tb5Si2Ge2 Thin Films Produced by Electron-beam Evaporation

“…2 depicted the SEM images of the surface of EVP02 sample (noted that EVP01 has a similar microstructure) and the cross-section views of EVP02 and EVP02_Q1 (annealed). From these pictures, it is patent that evaporation is a good technique to grow dense and uniform films that remain unchanged even after post-thermal annealings, similar to previously observer for other thin film preparation using e-beam evaporation technique [13,14]. Furthermore, SEM images reveal that the Tb 5 Si 2 Ge 2 thin film thickness values are 440 and 364 nm for EVP01 and EVP02, respectively, and 335 and 289 nm for the heat-treated samples, EVP01_Q1 and EVP02_Q1, respectively.…”

“…Recently, many groups have reported the production of magnetocaloric thin films such as La 1-x Ca x MnO 3 [8], NiMnGa [9,10], FePt [11], Gd 5 Si 2.09 Ge 1.91 [12], Gd [13,14], etc., by different processing techniques and on different substrates, always aiming the tuning of the magnetocaloric effect. Materials of the R 5 (Si,Ge) 4 family, where R=rare earth, in particular the compounds based on gadolinium and terbium, with a Si/Ge ratio of one, have gained interest due to their giant magnetocaloric effect (GMCE) [15,16].…”

Magnetization of 2.6 T in gadolinium thin films

“…From the outset, oxidation in rare earth films is an obvious obstacle to obtaining fundamental properties and so to avoid this in Gd thin films impacting on the magnetic properties [13] various 3 approaches have been considered such as using thicker layers of around 700nm and more [11] as well as tungsten multilayer stacks [14][15] and aluminum, titanium, or silicon capping [16]. We established that using 5nm Ta seed and capping layers provided effective protection in our systems.…”

Magnetocaloric materials: From micro- to nanoscale

“…However, there are other factors playing an important role, such as the effect of H 2 content and substrate temperature (T S ) on the properties of thin (50 nm thick) Gd films grown by DC sputtering. 44 In contrast to what happens when N atoms penetrate interstitially the Gd lattice, compressing it and leading to a decrease of T C , it was observed that in fact the T C increases with raising T S (higher T S promotes higher H absorption) up to a limit, after which it did not increase further. Especially, the film prepared at T S 5 600°C was found to have a T C very close to the bulk value (292.5 K), where the good crystallinity and the c-axis preferential orientation were pointed as causes for this behavior.…”

“…In the literature, a wide range of T C values can be found, ranging from 260 to 295 K (which is approximately bulk Gd T C ). [41][42][43][44] For polycrystalline thin films, such T C distribution can be directly associated with the crystallite size distribution present in the film. However, there are other factors playing an important role, such as the effect of H 2 content and substrate temperature (T S ) on the properties of thin (50 nm thick) Gd films grown by DC sputtering.…”