Improving the crystallinity and magnetocaloric effect of the perovskite La_0.65Sr_0.35MnO₃ using microwave irradiation

Abstract

MW heating produces materials that are superior in terms of both structure and magnetic properties.

Probing the Defect-Induced Magnetocaloric Effect on Ferrite/Graphene Functional Nanocomposites and their Magnetic Hyperthermia

“…Indeed, the sample with the largest particle size NZF/G2 showed the best magnetic hyperthermia performance. The malignant cancer cells destroy at a local heating of the human body about 313–318 K (40–45 °C). , …”

“…The malignant cancer cells destroy at a local heating of the human body about 313−318 K (40−45 °C). 1,69 The NZF and NZF/G nanocomposites show insignificant heating efficiency sufficient for the hyperthermia treatment as they exhibit weak magnetic entropy change (2.2 × 10 −4 to 0.66 × 10 −4 J•kg −1 •K −1 at 285 K) at close to RT. However, it offers a relation between the heating rate estimated from the nonadiabatic hyperthermia measurement and isothermal magnetic entropy change obtained from the adiabatic condition as shown in Figure 9b.…”

Observation of enhanced magnetic entropy change near room temperature in Sr-site deficient La0.67Sr0.33MnO3 manganite

“…Moreover, different rare Earth ions having the same oxidation state such as MnO 3 , MnO 3 and MnO 3 also exhibit different exchange interactions as well as different magnetic and electrical transport properties due to the difference in the average A-site ionic radius. 22–27 It is understood that, in doped manganites, the double exchange (DE) interaction via the Mn 3+ –O 2− –Mn 4+ ions is responsible for the ferromagnetic (FM) behaviour and the superexchange (SE) interaction through Mn 3+ –O 2− –Mn 3+ and Mn 4+ –O 2− –Mn 4+ ions are responsible for the antiferromagnetic (AFM) behaviour. This indicates that the strength of the competing exchange interactions and magnetic properties are eventually affected by different factors such as rare Earth substitution at the A-site, replacement of manganese by other transition elements, the introduction of deficiency at A and A′- sites, etc.…”