Magnetocaloric effect of Gd-based microwires from binary to quaternary system Y F Wang, F X Qin, Y H Wang, H Wang, R Das, M H Phan, and H X Peng Citation: AIP Advances 7, 056422 (2017); doi: 10.1063/1.4975356 View online: http://dx.doi.org/10.1063/1.4975356 View Table of Contents: http://aip.scitation.org/toc/adv/7/5 Published by the American Institute of Physics Articles you may be interested in Universal field dependence of conventional and inverse magnetocaloric effects in DyCo2Si2 AIP Advances 121, 043901043901 (2017); 10.1063/1.4974302 AIP ADVANCES 7, 056422 (2017) Magnetocaloric effect of Gd-based microwires from binary to quaternary system Y F Wang,1 F X Qin,1,a Y H Wang,1 H Wang,1 R Das,2 M H Phan,2 and H X Peng1 Institute for Composites Science Innovation (InCSI), School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China Department of Physics, University of South Florida, Tampa, Florida 33620, USA (Presented November 2016; received 23 September 2016; accepted 15 November 2016; published online 30 January 2017) We have studied the magnetocaloric effect (MCE) of Gd-based amorphous microwires from binary to quaternary system We find that with increase of components from binary GdNi to ternary GdNiCo, there is a significant increase in magnetic entropy change (∆Sm ) from 1.43 to 2.73 J · kg-1 · K -1 and an increase of temperature interval from 90K to 115K; further comparison between the quaternary GdNiCoDy and ternary GdNiCo shows a continuing increase of temperature interval while retaining the similar ∆Sm Such an improvement of MCE can be ascribed to the enhancement of amorphicity with increasing number of components, which leads to the improved magnetic softness and homogeneity The increase of the Curie temperature with increasing number of components also indicates the enhanced Ruderman– Kittel–Kasuya–Yosida (RKKY) magnetic interactions caused by the addition of alloying elements as comparing binary, ternary and quaternary system or by optimized composition in terms of such as Ni/Co ratio in a typical ternary system of GdNiCo These results have demonstrated that appropriately designed Gd-based microwires are very useful for active magnetic refrigeration in the liquid nitrogen temperature regime © 2017 Author(s) All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/) [http://dx.doi.org/10.1063/1.4975356] Modern society relies very much on readily available refrigeration Current refrigeration technology for cooling applications is mainly based on vapor compression, which has already reached an upper limit of cooling efficiency and is harmful to our living environment due to the usage of hazardous gas such as chlorofluorocarbons (CFCs) and hydro-chlorofluorocarbons (HCFCs).1 To meet the requirement of environmental friendliness and energy saving, magnetic refrigeration (MR) based on the magnetocaloric effect (MCE),2 emerges as the most promising alternative to conventional refrigerators, through a long time of continuous and in-depth research.3 The MCE is defined as the adiabatic temperature change (∆Tad ) of a magnetic material in response to a varying magnetic field (like magnetization and demagnetization), the essence of which is the isothermal magnetic entropy change (∆Sm ) due to the aligning or disturbing of the magnetic dipoles of atoms when a field is applied or removed So ∆Tad and ∆Sm are often considered to be two important parameters for characterizing MCEs in magnetic materials In view of its practical application, however, the refrigerant capacity (RC) is a more reasonable figure to characterize the cooling efficiency of magnetic materials, which is defined as the integration of −∆Sm (T) from the temperature of cold sink to hot sink in an ideal refrigeration cycle.4 Therefore, a desired magnetocaloric material should possess a large magnetic entropy change (∆Sm ) over a wide temperature range, resulting in the large RC.5 On account of the giant magnetocaloric effect (GMCE) discovered in Gd5 (Six Ge1-x )4 (0