Enhanced magnetocaloric response in Cr∕Mo containing Nanoperm-type amorphous alloys

Abstract

The magnetocaloric effect of Fe76Cr8−xMoxCu1B15 (x=0,4) alloys is studied. Although the combined addition of Cr and Mo is more efficient in tuning the Curie temperature of the alloy, the Mo-free alloy presents a higher magnetocaloric response. The refrigerant capacity (RC) for the Mo-containing alloy is comparable to that of Gd5Ge1.9Si2Fe0.1 (for a field of 50kOe, RC=273Jkg−1 for the Mo alloy vs 240Jkg−1 for the Gd-based one), with a larger temperature span of the optimal refrigeration cycle (250K vs 90K, respectively). The restriction of the temperature span to 90K gives RC=187Jkg−1 for the Mo alloy. A master curve behavior for the magnetic entropy change is also evidenced.

Achieving tailorable magneto-caloric effect in the Gd-Co binary amorphous alloys

“…[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Metallic glasses undergo a second order magnetic transition and exhibit a broadened magnetic entropy change peak. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Therefore, although the peak values of magnetic entropy change (-∆S m peak ) for the metallic glasses are not as high as some of the crystalline alloys, the amorphous alloys still have evoked intensive interests because their refrigeration capacity (RC) are usually several times higher than that of the crystalline alloys. Our recent results have shown that the RC can reach an ultra-high value of above 800 J·kg −1 under 5 T, accompanied with a relatively high -∆S m peak value of nearly 10 J·kg −1 ·K −1 under 5 T in some of the Gd-based metallic glasses.…”

Magnetocaloric effect in Mn-containing Hitperm-type alloys

“…This proposition was subsequently confirmed with experimental results for other amorphous alloys. 18,23 Figure 3 shows the master curve behavior of the magnetic entropy change curves of the studied alloys. This confirms, for this particular alloy series, the predictions of a master curve behavior for different alloy compositions of the same series.…”

“…8 More recently, soft magnetic amorphous alloys are getting increasing attention as low-cost candidates for magnetic refrigeration. [9][10][11][12][13][14][15][16][17][18] ͑According to a well-known bibliographic database, more than 36% of the literature on the magnetocaloric effect in amorphous materials were published since 2005. Considering only the magnetocaloric effect in transition-metal-based amorphous alloys, more than 50% of the papers studying these materials were published since then.͒ Although the maximum magnetic entropy change, ͉⌬S M pk ͉, for these alloys is modest when compared to that of rare-earth-based materials, 1,6 the remarkable difference in material costs is an incentive for studying their suitability as magnetic refrigerants.…”

“…22 Under some circumstances ͑namely, alloy series with similar values of the critical exponents͒, this master curve can also be extended to series of alloys with different compositions, being a powerful tool for making reasonable extrapolations to field and/or temperatures outside the available experimental range in some laboratories. 18,23 Up to date, there is no published information about the magnetocaloric effect in Hitperm-type alloys, which constitute one of the well-known families of nanocrystalline alloys coming from amorphous precursors. 24 Although these alloys have a high saturation magnetization, the presence of Co in the alloys causes a higher Curie temperature, T C , of the amorphous material.…”

MAGNETIC PROPERTIES AND MAGNETOCALORIC EFFECT OF Fe90-xPrxZr10 RAPIDLY QUENCHED ALLOYS

“…Many researchers have focused on magnetocaloric materials with amorphous or nanocrystalline structure [1][2][3][4]. One of the most typical materials is amorphous alloys.…”