Low-temperature high magnetic field powder x-ray diffraction setup for field-induced structural phase transition studies from 2 to 300 K and at 0 to 8-T field

Aga Shahee; Shivani Sharma; Dhirendra Kumar; Poonam Yadav; Preeti Bhardwaj; Nandkishor Ghodke; Kiran Singh; N P Lalla; P Chaddah

doi:10.1063/1.4963843

Low-temperature high magnetic field powder x-ray diffraction setup for field-induced structural phase transition studies from 2 to 300 K and at 0 to 8-T field

Rev Sci Instrum. 2016 Oct;87(10):105110. doi: 10.1063/1.4963843.

Authors

Aga Shahee¹, Shivani Sharma¹, Dhirendra Kumar¹, Poonam Yadav¹, Preeti Bhardwaj¹, Nandkishor Ghodke¹, Kiran Singh¹, N P Lalla¹, P Chaddah¹

Affiliation

¹ UGC-DAE Consortium for Scientific Research, University Campus, Khandawa Road, Indore, MP 452001, India.

PMID: 27802723
DOI: 10.1063/1.4963843

Abstract

A low-temperature and high magnetic field powder x-ray diffractometer (XRD) has been developed at UGC-DAE CSR (UGC: University Grant Commission, DAE: Department of Atomic Energy, and CSR: Consortium for scientific research), Indore, India. The setup has been developed around an 18 kW rotating anode x-ray source delivering Cu-K_α x-rays coming from a vertical line source. It works in a symmetric θ-2θ parallel beam geometry. It consists of a liquid helium cryostat with an 8 T split-pair Nb-Ti superconducting magnet comprising two x-ray windows each covering an angular range of 65°. This is mounted on a non-magnetic type heavy duty goniometer equipped with all necessary motions along with data collection accessories. The incident x-ray beam has been made parallel using a parabolic multilayer mirror. The scattered x-ray is detected using a NaI detector through a 0.1° acceptance solar collimator. To control the motions of the goniometer, a computer programme has been developed. The wide-angle scattering data can be collected in a range of 2°-115° of 2θ with a resolution of ∼0.1°. The whole setup is tightly shielded for the scattered x-rays using a lead hutch. The functioning of the goniometer and the artifacts arising possibly due to the effect of stray magnetic field on the goniometer motions, on the x-ray source, and on the detector have been characterized by collecting powder XRD data of a National Institute of Standards and Technology certified standard reference material LaB₆ (SRM-660b) and Si powder in zero-field and in-field conditions. Occurrence of field induced structural-phase transitions has been demonstrated on various samples like Pr_0.5Sr_0.5MnO₃, Nd_0.49Sr_0.51MnO_3-δ and La_0.175Pr_0.45Ca_0.375MnO₃ by collecting data in zero field cool and field cool conditions.