STRUCTURAL, TRANSPORT AND MAGNETOTRANSPORT IN NONMAGNETIC Al3+ DOPED MIXED VALENT La0.7Ca0.3Mn1-XAlXO3 MANGANITES

2012 ◽  
Vol 26 (24) ◽  
pp. 1250136 ◽  
Author(s):  
JALSHIKHABA S. RATHOD ◽  
UMA KHACHAR ◽  
R. R. DOSHI ◽  
P. S. SOLANKI ◽  
D. G. KUBERKAR
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Structural Phase ◽  
Concentration Field ◽  
Structural Disorder ◽  
Orthorhombic Structure ◽  
Temperature Dependent ◽  
Metal Insulator ◽  
Ceramic Method ◽  
Xrd Studies

We report the modifications in the transport and magnetotransport in La 0.7 Ca 0.3 Mn 1-x Al x O 3 (LCMAO); x = 0.0, 0.02, 0.04, 0.06, 0.08 and 0.1 polycrystalline manganites synthesized by conventional ceramic method. XRD studies reveal the single phasic orthorhombic structure for all the Al -doped LCMO samples without any detectable impurities and structural phase transition. SEM micrographs show island-like grain growth in all the samples studied. Transport measurements indicate an increase in resistivity and decrease in metal-insulator (M-I) transition temperature (TP) with the increase in Al -concentration. Field and temperature dependent variation in MR for all the Al (x) doped LCMO samples has been discussed in detail in the light of substitution induced structural disorder.

The structural phase transition process of free-standing monoclinic vanadium dioxide micron-sized rods: temperature-dependent Raman study

RSC Advances ◽  
2015 ◽  
Vol 5 (101) ◽  
pp. 83139-83143 ◽  
Author(s):  
Huafang Zhang ◽  
Quanjun Li ◽  
Pengfei Shen ◽  
Qing Dong ◽  
Bo Liu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Vanadium Dioxide ◽  
Structural Phase ◽  
Transition Process ◽  
Temperature Dependent ◽  
Free Standing ◽  
Lower Phase ◽  
Phase Transition Process ◽  
Raman Study

Micro-sized rods show a lower phase transition temperature than nano-sized rods, and this is interpreted on the basis of nucleating defects.

Enhanced Néel temperature in EuSnP under pressure

2019 ◽  
Vol 48 (16) ◽  
pp. 5327-5334 ◽  
Author(s):  
Xin Gui ◽  
Gregory J. Finkelstein ◽  
David E. Graf ◽  
Kaya Wei ◽  
Dongzhou Zhang ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Transition Temperature ◽  
Structural Phase ◽  
Antiferromagnetic Transition ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Resistivity Measurements ◽  
Temperature Dependent Resistivity

The high-pressure single crystal X-ray diffraction results for EuSnP are reported with no structural phase transition below ∼6.2 GPa. Temperature-dependent resistivity measurements up to 2.15 GPa indicate that the antiferromagnetic transition temperature (TN) is significantly enhanced under pressure.

scholarly journals Effect of Sintering Temperature on Metal-Insulator Phase Transition in La1-xCaxMnO3 Perovskites

2020 ◽  
Vol 2 (1) ◽  
pp. 37-42
Author(s):  
Arunachalam M ◽  
Thamilmaran P ◽  
Sakthipandi K
Keyword(s):  
Phase Transition ◽  
Bulk Modulus ◽  
Sintering Temperature ◽  
Magnetic Sensors ◽  
Temperature Dependent ◽  
Metal Insulator ◽  
Wide Range ◽  
Different Temperatures ◽  
Insulator Phase Transition

Lanthanum calcium based perovskites are found to be advantageous for the possible applications in magnetic sensors/reading heads, cathodes in solid oxide fuel cells, and frequency switching devices. In the present investigation La0.3Ca0.7MnO3 perovskites were synthesised through solid state reaction and sintered at four different temperatures such as 900, 1000, 1100 and 1200˚ C. X-ray powder diffraction pattern confirms that the prepared La0.3Ca0.7MnO3 perovskites have orthorhombic structure with Pnma space group. Ultrasonic in-situ measurements have been carried out on the La0.3Ca0.7MnO3 perovskites over wide range of temperature and elastic constants such as bulk modulus of the prepared La0.3Ca0.7MnO3 perovskites was obtained as function of temperature. The temperature-dependent bulk modulus has shown an interesting anomaly at the metal-insulator phase transition. The metal insulator transition temperature derived from temperature-dependent bulk modulus increases from temperature 352˚ C to 367˚ C with the increase of sintering temperature from 900 to 1200˚ C.

Orbital change manipulation metal–insulator transition temperature in W-doped VO2

2015 ◽  
Vol 17 (17) ◽  
pp. 11638-11646 ◽  
Author(s):  
Xinfeng He ◽  
Yijie Zeng ◽  
Xiaofeng Xu ◽  
Congcong Gu ◽  
Fei Chen ◽  
...  
Keyword(s):  
Phase Transition ◽  
Infrared Spectroscopy ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
First Principles ◽  
Insulator Transition ◽  
First Principles Calculations ◽  
Orbital Structure ◽  
Metal Insulator Transition ◽  
Metal Insulator

Using ultraviolet-infrared spectroscopy and first principles calculations, it is revealed that changes in the orbital structure can regulate the W-doped VO2 phase transition temperature.

scholarly journals Role of thermal strain in the metal-insulator and structural phase transition of epitaxialVO2films

2016 ◽  
Vol 93 (18) ◽  
Author(s):  
V. Théry ◽  
A. Boulle ◽  
A. Crunteanu ◽  
J. C. Orlianges ◽  
A. Beaumont ◽  
...  
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Thermal Strain ◽  
Metal Insulator
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