Improvement on Magnetocaloric Effect through Structural Evolution in Gadolinium Borate Halides Ba2Gd(BO3)2X (X = F, Cl)

Yuwei Chen; Pifu Gong; Ruixin Guo; Feidi Fan; Jun Shen; Guochun Zhang; Heng Tu

doi:10.1021/acs.inorgchem.3c02139

Improvement on Magnetocaloric Effect through Structural Evolution in Gadolinium Borate Halides Ba₂Gd(BO₃)₂X (X = F, Cl)

Inorg Chem. 2023 Sep 25;62(38):15584-15592. doi: 10.1021/acs.inorgchem.3c02139. Epub 2023 Sep 14.

Authors

Yuwei Chen^{1

2}, Pifu Gong^{1

2}, Ruixin Guo^{1

2}, Feidi Fan^{1

2}, Jun Shen³, Guochun Zhang^{1

2}, Heng Tu^{1

2}

Affiliations

¹ Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
³ School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China.

PMID: 37708428
DOI: 10.1021/acs.inorgchem.3c02139

Abstract

A new Gd³⁺-containing borate Ba₂Gd(BO₃)₂F has been successfully grown via the high-temperature solution method using BaF₂-NaF-B₂O₃ flux. Ba₂Gd(BO₃)₂F crystallizing in the orthorhombic space group Pnma is with lattice parameters a = 7.571(4) Å, b = 10.424(5) Å, c = 8.581(4) Å, α = β = γ = 90°, and Z = 2. Its three-dimensional framework was constructed from interesting pinwheel-like [Gd(BO₃)F]_∞ layers bridged by sharing [BO₃]^3-, which is different from the [Gd(BO₃)]_∞ layer in the model structure Ba₂Gd(BO₃)₂Cl. The magnetic measurements indicated that Ba₂Gd(BO₃)₂F has a larger magnetocaloric effect with -ΔS_m,max = 27.82 J·kg^-1·K^-1at 2 K and 9 T than that of Ba₂Gd(BO₃)₂Cl under the same conditions. Moreover, thermal stability, infrared spectrum (IR), and ultraviolet-visible-near-infrared diffuse reflectance spectrum were carried out to characterize the title compounds. The first-principles computations also looked into the electronic band structures, densities of states, and refractive indices.