Evidence of direct correlation between out-of-plane lattice parameter and metal-insulator transition temperature in oxygen-depleted manganite thin films

Ag -doped La 0.7 Ca 0.3 MnO 3 (LCMO) films were prepared on silicon substrate by RF magnetron sputtering. The dependences of transport properties on annealing temperature were explored. It is shown that the resistivity of the samples decreases and the metal–insulator transition temperature shifts to higher temperature with the increase in annealing temperature. Two metal–insulator transition temperatures are presented in the R – T plots of Ag -doped LCMO films, which can be explained by the Ag 1+ substitution of La 3+ to form La 1-x Ag x MnO 3 compound. Compared with LCMO thin films, Ag -doping can observably improve the TM-I and decrease the resistivity of the samples.

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Thermopower analysis of metal-insulator transition temperature modulations in vanadium dioxide thin films with lattice distortion

Physical Review B ◽

10.1103/physrevb.92.035302 ◽

2015 ◽

Vol 92 (3) ◽

Cited By ~ 20

Author(s):

Takayoshi Katase ◽

Kenji Endo ◽

Hiromichi Ohta

Keyword(s):

Thin Films ◽

Transition Temperature ◽

Vanadium Dioxide ◽

Lattice Distortion ◽

Insulator Transition ◽

Metal Insulator Transition ◽

Metal Insulator ◽

Vanadium Dioxide Thin Films

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LSMO thin films with high metal–insulator transition temperature on buffered SOI substrates for uncooled microbolometers

Applied Surface Science ◽

10.1016/j.apsusc.2014.05.051 ◽

2014 ◽

Vol 312 ◽

pp. 30-33 ◽

Cited By ~ 19

Author(s):

Š. Chromik ◽

V. Štrbík ◽

E. Dobročka ◽

T. Roch ◽

A. Rosová ◽

...

Keyword(s):

Thin Films ◽

Transition Temperature ◽

Insulator Transition ◽

Metal Insulator Transition ◽

Metal Insulator ◽

High Metal ◽

Soi Substrates

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Giant Magnetoresistance Phenomenon in Laser Ablated La0.6y0.07ca0.33mnox Thin Films

MRS Proceedings ◽

10.1557/proc-397-241 ◽

1995 ◽

Vol 397 ◽

Cited By ~ 2

Author(s):

Dhananjay Kumar ◽

R. Kalyanaraman ◽

J. Narayan ◽

David K. Christen

Keyword(s):

Thin Films ◽

Giant Magnetoresistance ◽

Lattice Parameter ◽

Insulator Transition ◽

X Ray Diffraction ◽

Metal Insulator Transition ◽

Metal Insulator ◽

Spin Dependent Scattering ◽

Resistance Peak

ABSTRACTMicrostructural and magnetoresistance properties of La0.6Y0.07Ca0.33MnOx (Y-doped LCMO) thin films grown in-situ by pulsed laser ablation have been studied. Transmission election microscopy and x-ray diffraction measurements have shown that the Y-doped LCMO thin films grow epitaxially on (100) LaAl03 substrates and are cubic with a lattice parameter of 3.849 ?. The as-deposited films exhibited a metal-insulator transition at 130 K and a giant magnetoresistance (GMR) at 125 K with a MR ratio (dR/RH) of 1500% in the presence of a magnetic field of 6 Tesla. Such a colossal value of MR ratio for as-deposited Y-doped LCMO films is quite promising keeping in view the fact that these films were unannealed and not optimized. We ascribe this magnetoresistance to spin-dependent electron scattering coupled with the presence of intervening O2. ions across Mn3+ and Mn4+ with suppressed separation between Mn-O layers caused by smaller sized Y-dopant. The effect of annealing on the positive-shift of metal-insulator transition temperature and the improvement in GMR ratio has also been discussed. We also report a non-ohmic response in the Y-doped LCMO films which is observed only in the region of the resistance peak and lends support to a conduction mechanism in these materials based on spin-dependent scattering of electrons.

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