Large Magnetovolume Effect Induced by Embedding Ferromagnetic Clusters into Antiferromagnetic Matrix of Cobaltite Perovskite

Ping Miao; Xiaohuan Lin; Akihiro Koda; Sanghyun Lee; Yoshihisa Ishikawa; Shuki Torii; Masao Yonemura; Takashi Mochiku; Hajime Sagayama; Shinichi Itoh; Kazutaka Ikeda; Toshiya Otomo; Yinxia Wang; Ryosuke Kadono; Takashi Kamiyama

doi:10.1002/adma.201605991

Large Magnetovolume Effect Induced by Embedding Ferromagnetic Clusters into Antiferromagnetic Matrix of Cobaltite Perovskite

Adv Mater. 2017 Jul;29(27). doi: 10.1002/adma.201605991. Epub 2017 May 8.

Authors

Ping Miao^{1

2}, Xiaohuan Lin³, Akihiro Koda^{1

2}, Sanghyun Lee¹, Yoshihisa Ishikawa¹, Shuki Torii¹, Masao Yonemura^{1

2}, Takashi Mochiku⁴, Hajime Sagayama^{1

2}, Shinichi Itoh^{1

2}, Kazutaka Ikeda^{1

2}, Toshiya Otomo^{1

2}, Yinxia Wang³, Ryosuke Kadono^{1

2}, Takashi Kamiyama^{1

2}

Affiliations

¹ Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tokai, Ibaraki, 319-1106, Japan.
² Department of Materials Structure Science, Sokendai (The Graduate University for Advanced Studies), Tokai, Ibaraki, 319-1106, Japan.
³ State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
⁴ National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0047, Japan.

PMID: 28480977
DOI: 10.1002/adma.201605991

Abstract

Materials that show negative thermal expansion (NTE) have significant industrial merit because they can be used to fabricate composites whose dimensions remain invariant upon heating. In some materials, NTE is concomitant with the spontaneous magnetization due to the magnetovolume effect (MVE). Here the authors report a new class of MVE material; namely, a layered perovskite PrBaCo₂ O_5.5+_x (0 ≤ x ≤ 0.41), in which strong NTE [β ≈ -3.6 × 10^-5 K^-1 (90-110 K) at x = 0.24] is triggered by embedding ferromagnetic (F) clusters into the antiferromagnetic (AF) matrix. The strongest MVE is found near the boundary between F and AF phases in the phase diagram, indicating the essential role of competition between the F-clusters and the AF-matrix. Furthermore, the MVE is not limited to the PrBaCo₂ O_5.5+_x but is also observed in the NdBaCo₂ O_5.5+_x . The present study provides a new approach to obtaining MVE and offers a path to the design of NTE materials.

Keywords: magnetovolume effect; muon spin relaxation; negative thermal expansion; neutron powder diffraction.