ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Manganites of general formula ABMnO3 (where A is a trivalent rare-earth ion and B is adivalent dopant) have interesting properties, namely colossal magnetoresistance and theirapplicability as materials for active magnetic regenerators. La0.70Sr0.30MnO3 (LSMO) is aferromagnet presenting considerable magnetocaloric effect, with operating temperature TC ~ 370 Kand magnetic entropy variation comparable to pure Gadolinium. The high value of TC makes LSMOunsuitable for room-temperature magnetic refrigeration applications, but by substituting La with thehigh-magnetic moment ion Er, TC is lowered and total magnetic entropy increases. We have found alimit of solid solubility of Er ions in LSMO, in samples prepared by either solid state or sol-geltechniques in previous works [1], in accordance with other authors [2]. We now present a moredetailed study of this limit of solubility, with more samples prepared with Er substitution close tothe solubility limit and SEM microscopy clearly showing the changes in microstructure caused bythe formation of a secondary ErMnO3 phase, in accordance with x-ray diffraction data and TCvariation along the series. The magnetocaloric properties of the series are also presented, showingthe increase of Relative Cooling Power along the series, in applied magnetic fields up to 1 T
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.587-588.338.pdf
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