Exchange coupling induced antiferromagnetic-ferromagnetic transition in Pr0.5Ca0.5MnO3/La0.5Ca0.5MnO3Pr_{0.5}Ca_{0.5}MnO_3/La_{0.5}Ca_{0.5}MnO_3 superlattices

Superlattices built from two antiferromagnetic (AFM) charge/orbital order compounds, $Pr_{0.5}Ca_{0.5}MnO_3$ and $La_{0.5}Ca_{0.5}MnO_3$, have been studied as the thickness of $La_{0.5}Ca_{0.5}MnO_3$ ($LCMO$) varied. High structural quality thin films were obtained on $LaAlO_3$ substrates using the pulsed laser deposition technique. An antiferromagnetic-to-ferromagnetic transition, in addition to an enhancement of the coercivity, are observed as the $LCMO$ layer thickness increases. The small shift in the origin of the field-cooled hysteresis loop along the field axis indicates the presence of ferromagnetic and antiferromagnetic phases in the superlattices. We attribute these features to the AFM spin fluctuations at the $Pr_{0.5}Ca_{0.5}MnO_3/La_{0.5}Ca_{0.5}MnO_3$ interfaces resulting from the strain effects.Comment: To be published in Phys. Rev.

Beef growth rate studies- A report on the Pardelup Prison farms trials.

In an earlier issue of this Journal (Volume 5 No. 4 page 479), July-August, 1956, there appeared an introduction to the reports on weight change observations made on three properties in Western Australia. The work was undertaken as part of an Australia-wide plan to accumulate data of normal trends in growth under existing conditions as a prerequisite to designing experiments with various changes in husbandry

The interparticle interaction and crossover in critical lines on field-temperature plane in Pr0.5_{0.5}Sr0.5_{0.5}MnO3_{3} nanoparticles

The magnetic properties and the effects of interparticle interaction on it have been studied in nanoparticles of half doped Pr$_{0.5}$Sr$_{0.5}$MnO$_{3}$. Three samples consisting of nanoparticles of different average particle sizes are synthesized to render the variation in interparticle interaction. Though all the samples crystallize in the same structure to that of their bulk compound, the low temperature ferromagnetic-antiferromagnetic transition, which is present in bulk compound, is not evident in the nanoparticles. Linear as well as nonlinear ac susceptibility coupled with dc magnetic measurements have shown the superparamagnetic behavior of these nanoparticles where the blocking temperature increases with the increasing particle size. Presence of interparticle interaction is confirmed from the temperature variation of coercive field and the analysis of frequency dependent ac susceptibility. We have identified the nature of this interaction to be of dipolar type, and show that its strength decreases with the increasing particle size. The effect of this dipolar interaction on magnetic properties is intriguing as the compounds exhibit crossover from de Almeida-Thouless to Gabay-Toulouse like critical lines on field-temperature plane above their respective interaction field. In agreement with theoretical prediction, we infer that this crossover is induced by the unidirectional anisotropy arising from interparticle interaction, and this is confirmed from the presence of exchange bias phenomenon.Comment: To appear in Phys. Rev.

Weight trends in fattening cattle

This work was commenced as part of the co-ordinated plan of investigations into beef growth rates in the southern regions of Australia, and was referred to in the introductory note Beef Growth Rate Studies published in this Journal (Vol. 5, No. 4, July-August, 1956). For the period 1950 to 1953 inclusive, an endeavour was made to procure evidence showing the trend in weight gain according to the seasons of the year. In the 1953-54 season and since, the work has been varied to measure the growth rate of steers which were grazed on irrigated pasture during the summer months, in comparison with others grazed on dry pasture at that time

Weight trends in fattening cattle - Six years\u27 trials at Wokalup Research Station - continued

All groups in Projects 1, 2 and 3 and the groups on unirrigated pasture in Project 4, have shown a similarity in seasonal growth trends. There was an actively growing period from about June to December or January in each year. For the remainder of the year weights either remained relatively constant or losses were incurred. In this discussion, reference will be made to these periods, as the actively growing and the static or losing periods

Revised grade herd recording rules

The rules governing the operation of Grade Herd Recording under the Western Australian Herd Improvement Scheme were recently revised and modified to meet existing conditions. The revised rules are published for the information and guidance of interested dairy farmers

Beef growth rate studies

The Australian Agricultural Council in 1948 approved a co-ordinated plan of investigating beef growth rates in the southern regions of Australia. Considerable attention had been given to the problems of the beef industry in Northern Australia, but it was felt that the value of the southern agricultural areas as a source of fat cattle as well as for rapid and economical fattening, was not fully appreciated. The Animal Production Committee and its Technical Sub-committee on Beef Cattle were charged with the responsibility of organising, with the State Departments of Agriculture work in each of the States of New South Wales, Victoria, Tasmania, South Australia and Western Australia