Surface effect ferromagnetism in pure and reduced strontium titanate

A room temperature ferromagnetic hysteresis is observed in single crystal strontium titanate substrates as purchased from several manufacturers. It was found that polishing all sides of the substrates removed this observed hysteresis, suggesting that the origin of the ferromagnetic behavior resides on the surface of the substrates. X-ray diffraction and energy dispersive x-ray spectra were measured however they were unable to detect any impurity phases. In similar semiconducting oxides it was previously suggested that ferromagnetism could originate in oxygen vacancies or from disorder within the single crystal. To this end substrates were annealed in both air and vacuum in a range of temperatures (600°C to 1100°G) to both create bulk oxygen vacancies and to heal surface damage. Annealing in vacuum was found to create a measureable number of oxygen vacancies however their creation could not be correlated to the ferromagnetic signal of the substrate. Annealing in air was found to effect the remnant moment of the substrate as well as the width of the x-ray diffraction peaks on the unpolished face, weakly suggesting a relation between surface based disorder and ferromagnetism. Argon ion bombardment was employed to create a layer of surface disorder in the polished crystal, however it was not found to induce ferromagnetism. It was found that acid etching was sufficient to remove the ferromagnetism from as purchased samples and similarly simulated handling with stainless steel tweezers was sufficient to re-create the ferromagnetism. It is suggested that the origin of this ferromagnetism in SrTi03 is surface contaminants (mainly iron).

The War, 8 March 1814 (vol. 2, no. 38, whole no. 90) - Newspaper

Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.

HG 238.80-238.90 Thin Section

Dark brown sediment with clasts ranging from small to medium in size and sub-angular to angular. Contains lineations and grain stacking throughout the sample. Rotation and comet structures can also be seen. Rotation structures can be seen around mainly the sub-angular clasts. Patches of clay can also be seen throughout the sample.

DE #6 260.90-261.0

Coarse grained sediment with clasts ranging from small to medium in size. Clast shape range from sub-angular to sub-rounded. Lineations are present throughout the sample. Edge-to-edge grain crushing, grain stacking, and comet structures can also be seen. Some grains are crushed into one another. Areas of finer sediment can also be seen.

HG 367.80-367.90

Dark grey sediment with clasts that range from small to medium. The clasts are mainly sub-rounded. Lineations are abundant with minor amounts of rotation structures and comet structures. Grain crushing can also be seen throughout the sample.

HG 493.80-493.90

Coarse brown sediment, with clasts ranging from small to large in size. Clast shape ranges from sub-angular to rounded. Lineations and grain crushing are common throughout the sample. It also contains comet structures and a few rotation structures. Many of the larger clasts are also fractured.

HG 28.75-28.90

This sample contains clasts that range from small to large. A few fractured grains can be seen. The grain shape ranges from angular to rounded. Rotation structures can be seen throughout the sample along with some edge-to-edge grain crushing.

HG 64.80-64.90

Dark brown sediment with clasts ranging from small to large in size. The clast shape ranges from angular to sub-rounded. Many of the larger clasts are fractured. Grain crushing is abundant throughout the sample. A few lineations can also be seen throughout the sample.

HG 129.75-129.90

Brown sediment with clasts ranging from small to medium in size. Clast shape ranges from angular to sub-rounded. Rotation structures are abundant in this sample. Edge-to-edge grain crushing, comet structures, and lineations can also be seen in this sample.

Barnes Wines, Limited By-Law No. 90

The By-Law summary states it is "a by-law relating generally to the transaction of the business and affairs of Barnes Wines, Limited". The sub headings of the bill are as follows: Head Office, Corporate Seal, Meetings of Shareholders, Directors, Officers, Notices, Interpretation.