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Chemical ordering suppresses large-scale electronic phase separation in doped manganites.

Zhu Y, Du K, Niu J, Lin L, Wei W, Liu H, Lin H, Zhang K, Yang T, Kou Y, Shao J, Gao X, Xu X, Wu X, Dong S, Yin L, Shen J - Nat Commun (2016)

Bottom Line: For strongly correlated oxides, it has been a long-standing issue regarding the role of the chemical ordering of the dopants on the physical properties.Our experimental results show that the chemical ordering of Pr leads to marked reduction of the length scale of electronic phase separations.Moreover, compared with the conventional Pr-disordered LPCMO system, the Pr-ordered LPCMO system has a metal-insulator transition that is ∼100 K higher because the ferromagnetic metallic phase is more dominant at all temperatures below the Curie temperature.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.

ABSTRACT
For strongly correlated oxides, it has been a long-standing issue regarding the role of the chemical ordering of the dopants on the physical properties. Here, using unit cell by unit cell superlattice growth technique, we determine the role of chemical ordering of the Pr dopant in a colossal magnetoresistant (La(1-y)Pr(y))(1-x)Ca(x)MnO3 (LPCMO) system, which has been well known for its large length-scale electronic phase separation phenomena. Our experimental results show that the chemical ordering of Pr leads to marked reduction of the length scale of electronic phase separations. Moreover, compared with the conventional Pr-disordered LPCMO system, the Pr-ordered LPCMO system has a metal-insulator transition that is ∼100 K higher because the ferromagnetic metallic phase is more dominant at all temperatures below the Curie temperature.

No MeSH data available.


Related in: MedlinePlus

Comparison of the FMM domain size.(a) Histogram of FMM domain size distribution of O-LPCMO (yellow) and R-LPCMO (blue). The domain size was analysised from five images for both samples at each temperature. The scanning region is 20 × 20 μm for each image. Inset show MFM images (7 × 14 μm) of R-LPCMO at 140 K and O-LPCMO at 220 K under 1 T field. (b) Temperature-dependent resistivity of O-LPCMO strip (black) and R-LPCMO strip (red).
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f4: Comparison of the FMM domain size.(a) Histogram of FMM domain size distribution of O-LPCMO (yellow) and R-LPCMO (blue). The domain size was analysised from five images for both samples at each temperature. The scanning region is 20 × 20 μm for each image. Inset show MFM images (7 × 14 μm) of R-LPCMO at 140 K and O-LPCMO at 220 K under 1 T field. (b) Temperature-dependent resistivity of O-LPCMO strip (black) and R-LPCMO strip (red).

Mentions: The most remarkable observation from the MFM study is the marked reduction of the domain size of the FMM phase in the O-LPCMO system. While the visual impression of this fact is already clear from the MFM images in Fig. 3, we make a quantitative comparison of the domain size of the R-LPCMO and the O-LPCMO films when they are in the vicinity of their corresponding MIT temperatures, that is, 140 and 220 K, respectively. We compare the FMM domain size at the same T/Tp rather than T/Tc, because it is hard to determine the domain size after percolation (or below MIT temperature) when most domains join together. Figure 4a shows the histogram of the size distribution of the FMM domains for the two films, with the inset showing the corresponding MFM images in colour scale (the details of domain size comparison at both 140 and 220 K can be found in Supplementary Fig. 8 and Supplementary Note 7). The average area per FMM domain is estimated to be ∼0.392 and ∼0.031 μm2 for the R-LPCMO and the O-LPCMO, respectively. While the FMM domains in the R-LPCMO film are in submicron scale as expected, the FMM domains of the O-LPCMO are significantly smaller.


Chemical ordering suppresses large-scale electronic phase separation in doped manganites.

Zhu Y, Du K, Niu J, Lin L, Wei W, Liu H, Lin H, Zhang K, Yang T, Kou Y, Shao J, Gao X, Xu X, Wu X, Dong S, Yin L, Shen J - Nat Commun (2016)

Comparison of the FMM domain size.(a) Histogram of FMM domain size distribution of O-LPCMO (yellow) and R-LPCMO (blue). The domain size was analysised from five images for both samples at each temperature. The scanning region is 20 × 20 μm for each image. Inset show MFM images (7 × 14 μm) of R-LPCMO at 140 K and O-LPCMO at 220 K under 1 T field. (b) Temperature-dependent resistivity of O-LPCMO strip (black) and R-LPCMO strip (red).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4829688&req=5

f4: Comparison of the FMM domain size.(a) Histogram of FMM domain size distribution of O-LPCMO (yellow) and R-LPCMO (blue). The domain size was analysised from five images for both samples at each temperature. The scanning region is 20 × 20 μm for each image. Inset show MFM images (7 × 14 μm) of R-LPCMO at 140 K and O-LPCMO at 220 K under 1 T field. (b) Temperature-dependent resistivity of O-LPCMO strip (black) and R-LPCMO strip (red).
Mentions: The most remarkable observation from the MFM study is the marked reduction of the domain size of the FMM phase in the O-LPCMO system. While the visual impression of this fact is already clear from the MFM images in Fig. 3, we make a quantitative comparison of the domain size of the R-LPCMO and the O-LPCMO films when they are in the vicinity of their corresponding MIT temperatures, that is, 140 and 220 K, respectively. We compare the FMM domain size at the same T/Tp rather than T/Tc, because it is hard to determine the domain size after percolation (or below MIT temperature) when most domains join together. Figure 4a shows the histogram of the size distribution of the FMM domains for the two films, with the inset showing the corresponding MFM images in colour scale (the details of domain size comparison at both 140 and 220 K can be found in Supplementary Fig. 8 and Supplementary Note 7). The average area per FMM domain is estimated to be ∼0.392 and ∼0.031 μm2 for the R-LPCMO and the O-LPCMO, respectively. While the FMM domains in the R-LPCMO film are in submicron scale as expected, the FMM domains of the O-LPCMO are significantly smaller.

Bottom Line: For strongly correlated oxides, it has been a long-standing issue regarding the role of the chemical ordering of the dopants on the physical properties.Our experimental results show that the chemical ordering of Pr leads to marked reduction of the length scale of electronic phase separations.Moreover, compared with the conventional Pr-disordered LPCMO system, the Pr-ordered LPCMO system has a metal-insulator transition that is ∼100 K higher because the ferromagnetic metallic phase is more dominant at all temperatures below the Curie temperature.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.

ABSTRACT
For strongly correlated oxides, it has been a long-standing issue regarding the role of the chemical ordering of the dopants on the physical properties. Here, using unit cell by unit cell superlattice growth technique, we determine the role of chemical ordering of the Pr dopant in a colossal magnetoresistant (La(1-y)Pr(y))(1-x)Ca(x)MnO3 (LPCMO) system, which has been well known for its large length-scale electronic phase separation phenomena. Our experimental results show that the chemical ordering of Pr leads to marked reduction of the length scale of electronic phase separations. Moreover, compared with the conventional Pr-disordered LPCMO system, the Pr-ordered LPCMO system has a metal-insulator transition that is ∼100 K higher because the ferromagnetic metallic phase is more dominant at all temperatures below the Curie temperature.

No MeSH data available.


Related in: MedlinePlus