An typical giant magnetoresistive (GMR) sample viz. La0.7Pb 0.3MnO3 has been irradiated by 50 MeVLi3+ ion beam. Irradiated samples have been studied from the measurement of resistivity down to 77 K in presence of 1.5 T magnetic field. Although magnetoresistance is not maximum at Tim as the samples are polycrystalline, however, a small peak like structure has been found around Tim. The peak is most prominent for maximum fluence. © 2003 Elsevier Ltd. All rights reserved.

ARITRA BANERJEE

Physics

S CHATTOPADHYAY

A SARKAR

R KUMAR

B K CHAUDHURI

D BANERJEE

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Study of irradiation induced changes in La0.7Pb0.3MnO3

Radiation Measurements

Present report deals with the effect of disorder on Bi-2212 type high Tc superconducting and LCMO type CMR oxide materials. Ion irradiation (50 MeV Li3+ beam) creates high level of disorder in the superconducting system and as a result increase of room temperature resistivity (ρ300) has been observed. Radiation induced point defects cause an increased dρ/dT in the metal-like regime of Bi-2212. Similar increase of dρ/dT in the FM (ferromagnetic and metal-like) state has also been found in LCMO system. Enhancement of metal-like behavior is unusual in the sense that a simultaneous decrease of Tmi (metal-insulator transition temperature for LCMO) or Tc (superconducting transition temperature for Bi-2212) due to irradiation has also been observed. Effect of the defects incorporated by other means like variation of heat treatment and ion irradiation has been investigated for a better understanding on the electrical transport in these complex materials. Results have been discussed in the light of their intrinsic granular nature. © 2005 Elsevier B.V. All rights reserved.

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

Unusual metal-like state in HTSC and CMR oxides

Polycrystalline La0.5Pb0.5Mn1-xCr xO3 (x = 0.075 and 0.15) samples have been irradiated with 50 MeV Li3+ ions with different fluences and the effects on the transport properties have been studied by means of the temperature and magnetic field dependent resistivity measurements. Due to Li3+ ion irradiation, the resistivity increases and the metal-insulator transition temperature (Tmi) decreases. At low temperatures (below T mi), a dominant contribution of the electron-magnon scattering process is observed for all the irradiated and unirradiated samples. The low temperature resistivity behavior as well as the magnetoresistance is modified due to irradiation. The changes in the magnetotransport properties due to irradiation have been compared with the changes caused due to Mn site substitution. © 2005 Elsevier B.V. All rights reserved.

Radiation damage effects in CMR manganite materials

We report the low temperature (below the metal-insulator transition temperature Tim) resistivity and magnetoresistance (MR) behavior of 50 MeV Li3+ beam irradiated La0.7Pb0.3MnO 3 for three different fluences. Ion beam irradiation causes a decrease of Tim leading to the increase of insulating regime. Resistivity data of the unirradiated as well as irradiated samples fitted well with an equation of the form ρ = ρ0 + ρ 2.5T2.5 which indicates predominant contribution from the electron-magnon interaction (second term). The temperature dependent MR data of samples irradiated with different ion fluences follow the simple relation [MR = a + b/(T + C)] showing appreciable effect of radiation on the parameters a, b and C. The physical significance of the radiation effect on these parameters is not yet very clear. © 2004 Elsevier B.V. All rights reserved.

Effect of Li3+ irradiation on the transport properties of La0.7Pb0.3MnO3 type CMR material

Physical Review B

Magnetoresistance and magnetothermoelectric power ofLa0.5Pb0.5Mn1−xCrxO3

The Journal of Chemical Physics

Nature of small-polaron hopping conduction and the effect of Cr doping on the transport properties of rare-earth manganite La0.5Pb0.5Mn1−xCrxO3

Radiation Effects and Defects in Solids

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

Colossal Magnetoresistance, Charge Ordering and Related Properties of Manganese Oxides

Applied Physics Letters

Low-field magnetoresistive properties of polycrystalline and epitaxial perovskite manganite films

Study of 50 MeV Li3+ irradiation induced changes in La 0.7Pb0.3MnO3

Journal	Radiation Measurements
Publisher	-
ISSN	1350-4487
Open Access	No