Size-dependent structural and magnetic properties of chemically synthesized Co-Ni-Ga nanoparticles

Changhai Wang, Aleksandr A. Levin, Julie Karel, Simone Fabbrici, Jinfeng Qian, Carlos E. Violbarbosa, Siham Ouardi, Franca Albertini, Walter Schnelle, Jan Rohlicek, Gerhard H. Fecher, Claudia Felser

Research output: Contribution to journalArticleResearchpeer-review

22 Citations (Scopus)

Abstract

Phase transitions and magnetic properties of shape-memory materials can be tailored by tuning the size of the constituent materials, such as nanoparticles. However, owing to the lack of suitable synthetic methods for size-controlled Heusler nanoparticles, there is no report on the size dependence of their properties and functionalities. In this contribution, we present the first chemical synthesis of size-selected Co-Ni-Ga Heusler nanoparticles. We also report the structure and magnetic properties of the biphasic Co-Ni-Ga nanoparticles with sizes in the range of 30–84 nm, prepared by a SBA-15 nanoporous silicatemplated approach. The particle sizes could be readily tuned by controlling the loading and concentration of the precursors. The fractions and crystallite sizes of each phase of the Co-Ni-Ga nanoparticles are closely related to their particle size. Enhanced magnetization and decreased coercivity are observed with increasing particle size. The Curie temperature (Tc) of the Co-Ni-Ga nanoparticles also depends on their size. The 84 nm-sized particles exhibit the highest Tc (≈ 1,174 K) among all known Heusler compounds. The very high Curie temperatures of the Co-Ni-Ga nanoparticles render them promising candidates for application in high-temperature shape memory alloy-based devices. [Figure not available: see fulltext.].

Original languageEnglish
Pages (from-to)3421-3433
Number of pages13
JournalNano Research
Volume10
Issue number10
DOIs
Publication statusPublished - 1 Oct 2017
Externally publishedYes

Keywords

  • chemical synthesis
  • Co-Ni-Ga
  • magnetic properties
  • nanoparticles
  • size

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