title: Simple uniaxial pressure device for ac-susceptibility measurements suitable for closed cycle refrigerator system.
abstract: A simple design of the uniaxial pressure device for the measurement of ac-susceptibility at low temperatures using closed cycle refrigerator system is presented for the first time. This device consists of disc micrometer, spring holder attachment, uniaxial pressure cell, and the ac-susceptibility coil wound on stycast bobbin. It can work under pressure till 0.5 GPa and at the temperature range of 30-300 K. The performance of the system at ambient pressure is tested and calibrated with standard paramagnetic salts [Gd(2)O(3), Er(2)O(3), and Fe(NH(4)SO(4))(2)6H(2)O], Fe(3)O(4), Gd metal, Dy metal, superconductor (YBa(2)Cu(3)O(7)), manganite (La(1.85)Ba(0.15)MnO(3)), and spin glass material (Pr(0.8)Sr(0.2)MnO(3)). The performance of the uniaxial pressure device is demonstrated by investigating the uniaxial pressure dependence of La(1.85)Ba(0.15)MnO(3) single crystal with P||c axis. The Curie temperature (T(c)) decreases as a function of pressure with P||c axis (dT(c)dP(||c axis)=-11.65 KGPa) up to 46 MPa. The design is simple, is user friendly, and does not require pressure calibration. Measurement can even be made on thin and small size oriented crystals. The failure of the coil is remote under uniaxial pressure. The present setup can be used as a multipurpose uniaxial pressure device for the measurement of Hall effect and thermoelectric power with a small modification in the pressure cell.
authors.affiliation: High Pressure Low Temperature Lab, School of Physics, Bharathidasan University, Tiruchirappalli 620 024, India. sarumugam1963@yahoo.com
authors.forename: S
authors.initials: S
authors.lastname: Arumugam
authors.forename: N
authors.initials: N
authors.lastname: Manivannan
authors.forename: A
authors.initials: A
authors.lastname: Murugeswari
mesh_terms: D017097:Electric Impedance; D004560:Electricity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008365:Manometry / Q000295:instrumentation* / Q000379:methods; D011312:Pressure; D012034:Refrigeration / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity