Giant and isotropic magnetoresistance as huge as −53% was observed in magnetic manganese oxide La0.72Ca0.25MnOz films with an intrinsic antiferromagnetic spin structure. We ascribe this magnetoresistance to spin‐dependent electron scattering due to spin canting of the manganese oxide.

31p-S-4 Giant Magnetoresistance in Magnetic Manganese Oxide with Intrinsic Antiferromagnetic Spin Structure

This survey deals with 1/f noise in homogeneous semiconductor samples. A distinction is made between mobility noise and number noise. It is shown that there always is mobility noise with an /spl alpha/ value with a magnitude in the order of 10/sup -4/. Damaging the crystal has a strong influence on /spl alpha/, /spl alpha/ may increase by orders of magnitude. Some theoretical models are briefly discussed none of them can explain all experimental results. The /spl alpha/ values of several semiconductors are given. These values can be used in calculations of 1/f noise in devices. >

1/f Noise Sources

Ion beam induced surface and interface engineering

Mixed-valence perovskite manganites (Re1-xAxMnO3 where Re = rare earth, A = alkaline earth) provide a unique opportunity to study the relationships between the structure and the magnetotransport properties due to an interplay among charge carriers, magnetic coupling, orbital ordering and structural distortion. This makes these compounds very exciting from both the basic research and from the technological viewpoint. As the technology pursued with these materials requires film growth, extensive studies have been made on materials synthesis, structural and physical characterization and device fabrication. In this article, the results from the different experimental techniques and the effects of the deposition procedure of the manganite thin films are first reviewed. Second, the relation between the structural and the physical properties is mentioned, and the influence of strains discussed. Finally, possible applications of manganite thin films in spin electronics are presented.

http://iopscience.iop.org/article/10.1088/0953-8984/13/48/201/pdf

Colossal magnetoresistive manganite thin films

Ankylosis of the temporomandibular joint

The influence of swift heavy ion (SHI) irradiation on transport properties of epitaxial thin films of La0.75Ca0.25MnO3 (LCMO) is studied. The films were irradiated with 90 MeV16O beams and 250 MeV107 Ag beams at different fluence values. In the case of 90 MeV16O ions LCMO specimens were irradiated to 1011-1014 ions/cm2 and for 250 MeV107Ag ions with 1010–1013 ions/cm2. A systematic variation in Curie temperature (T c) or resistivity peak temperature (T p) has been observed. It has been noted that for both types of ions the T p increased for the specimen irradiated at 1011 ions/cm2 fluence. Further increase of fluence decreased the T p value and at higher fluence (1014 ions/cm2 for 90 MeV16O and 1013 ions/cm2 for 250 MeV107 Ag ions) the specimens showed no metal-to-insulator transition even at low temperature down to 77K. They show completely semiconducting behavior with high resistance values. These results are discussed in terms of SHI irradiation-induced structural distrotion and strain on thin...

Swift heavy ion irradiation effects on transport properties of epitaxial thin films of La1-xCaxMnO3

Epitaxial La0.7Ca0.3MnO3 thin films on the SrTiO3(100) surface have been irradiated with 250 MeV Ag17+ ions at different nominal fluence values in the range of 5×1010–4×1011 ions/cm2, resulting in columnar defects. At low fluences these defects cause changes in material properties that are small and scale linearly with dosage. Above a threshold fluence value ∼3×1011 ions/cm2 dramatic changes are observed, including an order of magnitude increase in the resistivity and 50 K drop in the Curie temperature. Transmission electron microscopy measurements show that the changes are associated with a phase transformation of the undamaged region between the columnar defects. The transformed phase has a diffraction pattern very similar to that seen in charge-ordered La0.5Ca0.5MnO3. We propose that above a critical level of ion damage, strains caused by the presence of the columnar defects induce a charge-ordering phase transition that causes the observed dramatic changes in physical properties. We speculate that a c...

Columnar defect induced phase transformation in epitaxial La0.7Ca0.3MnO3 films

Effect of disorder on the electrical resistance near the superconducting transition temperature in the paracoherence region of high temperature YBa 2 Cu 3 O 7− δ (YBCO) thin film superconductor is reported. For this, c -axis oriented YBa 2 Cu 3 O 7− δ thin films having superconducting transition width varying between 0.27 K and 6 K were deposited using laser ablation and high pressure oxygen sputtering techniques. Disorder in these films was further created by using 100 MeV oxygen and 200 MeV silver ions with varying fluences. It is observed that the critical exponent in the paracoherence region for films with high transition temperature and small transition width is in agreement with the theoretically predicted value ( γ  = 1.33) and is not affected by disorder, while for films with lower transition temperature and larger transition width the value of exponent is much larger as compared to that theoretically predicted and it varies from sample to sample and usually changes with disorder induced by radiation. This difference in the behaviour of the exponent has been explained on the basis of differences in the strength of weak links and the transition between temperatures T m and T c is interpreted as a percolation like transition with disorder.

Effect of disorder on the exponent in the coherence region in high temperature superconductors

Elastic Recoil Detection Analysis (ERDA) using ΔE - E telescope with gaseous ΔE detector is carried out for the first time for simultaneous detection of H alongwith other light elements C, N, and O in Diamondlike Carbon (DLC) films. The experimental data indicated the detection limit of 0.002 at.% for H and 0.006 at.% for N and O with 10% statistical inaccuracy.

Simultaneous detection of light elements by ERDA with gas-ionisation/Si ΔE-E detector telescope

We systematically reviewed the myofascial pain publications in the literature. The aim of this article is to review the methods of management and their outcome and factors associated with prognosis. The topics of interest in the diagnostic process are myofascial trigger points electromyography, jaw tracking, joint sound recorder, sonography, and vibratography, exclusion of other orofacial pain and temporomandibular disorders. Management modalities are occlusal therapy, physiotherapy, multidimensional rehabilitation antinociceptive therapy, anti-inflammatory and analgesics, muscle relaxants, stretch, and spray technique, transcutaneous electric nerve stimulation, and in severe cases botulinum toxin may be tried. The disease required interdisciplinary interaction in terms of occlusal therapy, antinociceptive therapy and physiotherapy because management of the disease may be influenced by the specialist primarily treating the patients.

G.K. Mehta

Papers

Swift heavy ion irradiation effects on transport properties of epitaxial thin films of La1-xCaxMnO3

Columnar defect induced phase transformation in epitaxial La0.7Ca0.3MnO3 films

Effect of disorder on the exponent in the coherence region in high temperature superconductors

Simultaneous detection of light elements by ERDA with gas-ionisation/Si ΔE-E detector telescope

Trends in management of myofacial pain.