TY - JOUR
T1 - Flux-mediated doping of Bi into (La,Sr)MnO3 films grown on NdGdO3 (110) substrates
AU - Mizufune, Koji
AU - Naganuma, Hiroshi
AU - Maruyama, Shingo
AU - Matsumoto, Yuji
N1 - Funding Information:
We thank Dr. CW Wu, MA-tek Japan for cross-sectional transmission electron microscopy observation and a fruitful discussion. This work was partly supported by KAKENHI (No. 15H03548) and by the Murata Science Foundation (072). This work was performed under the approval of the Photon Factory Program Advisory Committee (Proposal No. 2018G017).
PY - 2020/11/24
Y1 - 2020/11/24
N2 - Bi-doped (La,Sr)MnO3 [(Bi0.18La0.56Sr0.30) Mn0.96O3: BLSMO, tBLSMO = 63 nm] epitaxial films were grown on NaGdO3 (NGO) substrates by a flux-mediated doping approach. That is, the growth of a (La,Sr)MnO3 (LSMO) film under the coexistence of a Bi-based liquid flux leads to successful Bi doping into the LSMO film, though Bi is a highly volatile element. The composition analysis revealed that Sr preferentially existed in the film over the flux and that Sr has a larger distribution equilibrium coefficient (K) than those of Mn and La, which is one of the evidence that Bi has substituted for the La site. The obtained BLSMO films had a tetragonal distorted structure owing to a compressive strain from the NGO substrate, and the tetragonality and the crystallinity were enhanced by increasing the amount of Bi. The tetragonal distortion of the BLSMO films induced a perpendicular magnetic anisotropy. Both the Bi substitution at the La site and the ratio of Mn2+/Mn3+ increased from the film body to the surface, a magnetic moment was decreased to 0.6 μB/Mn. Although the magnetic moment was low, the Curie temperature of the BLSMO film was above room temperature (RT), and the magnetic entropy change |ΔSM| of 2.4 mJ/(cm3·K) was observed near RT. The BLSMO film is favored for magnetocaloric effect applications as well as spin-transfer-torque devices such as microwave oscillators.
AB - Bi-doped (La,Sr)MnO3 [(Bi0.18La0.56Sr0.30) Mn0.96O3: BLSMO, tBLSMO = 63 nm] epitaxial films were grown on NaGdO3 (NGO) substrates by a flux-mediated doping approach. That is, the growth of a (La,Sr)MnO3 (LSMO) film under the coexistence of a Bi-based liquid flux leads to successful Bi doping into the LSMO film, though Bi is a highly volatile element. The composition analysis revealed that Sr preferentially existed in the film over the flux and that Sr has a larger distribution equilibrium coefficient (K) than those of Mn and La, which is one of the evidence that Bi has substituted for the La site. The obtained BLSMO films had a tetragonal distorted structure owing to a compressive strain from the NGO substrate, and the tetragonality and the crystallinity were enhanced by increasing the amount of Bi. The tetragonal distortion of the BLSMO films induced a perpendicular magnetic anisotropy. Both the Bi substitution at the La site and the ratio of Mn2+/Mn3+ increased from the film body to the surface, a magnetic moment was decreased to 0.6 μB/Mn. Although the magnetic moment was low, the Curie temperature of the BLSMO film was above room temperature (RT), and the magnetic entropy change |ΔSM| of 2.4 mJ/(cm3·K) was observed near RT. The BLSMO film is favored for magnetocaloric effect applications as well as spin-transfer-torque devices such as microwave oscillators.
KW - Bi doping
KW - Flux-mediated doping
KW - LSMO
KW - Perpendicular magnetic anisotropy component
KW - Scanning transmission electron microscopy
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U2 - 10.1021/acsaelm.0c00718
DO - 10.1021/acsaelm.0c00718
M3 - Article
AN - SCOPUS:85096017069
VL - 2
SP - 3658
EP - 3666
JO - ACS Applied Electronic Materials
JF - ACS Applied Electronic Materials
SN - 2637-6113
IS - 11
ER -