An application step of applying an adhesive agent to an application area of a surface of a sintered R-T-B based magnet work, an adhesion step of allowing a particle size-adjusted powder that is composed of a powder of an alloy or a compound of a Pr—Ga alloy which is at least one of Dy and Tb to the application area of the surface of the sintered R-T-B based magnet work, and a diffusing step of heating it at a temperature which is equal to or lower than a sintering temperature of the sintered R-T-B based magnet work to allow the Pr—Ga alloy contained in the particle size-adjusted powder to diffuse from the surface into the interior of the sintered R-T-B based magnet work are included. The particle size of the particle size-adjusted powder is set so that, when powder particles composing the particle size-adjusted powder are placed on the entire surface of the sintered R-T-B based magnet work to form a particle layer which is not less than one layer and not more than three layers, the amount of Ga contained in the particle size-adjusted powder is in a range from 0.10 to 1.0% with respect to the sintered R-T-B based magnet work by mass ratio.

An application step of applying an adhesive agent to an application area of a surface of a sintered R-T-B based magnet work, an adhesion step of allowing a particle size-adjusted powder that is composed of a powder of an alloy or a compound of a Pr—Ga alloy which is at least one of Dy and Tb to the application area of the surface of the sintered R-T-B based magnet work, and a diffusing step of heating it at a temperature which is equal to or lower than a sintering temperature of the sintered R-T-B based magnet work to allow the Pr—Ga alloy contained in the particle size-adjusted powder to diffuse from the surface into the interior of the sintered R-T-B based magnet work are included. The particle size of the particle size-adjusted powder is set so that, when powder particles composing the particle size-adjusted powder are placed on the entire surface of the sintered R-T-B based magnet work to form a particle layer which is not less than one layer and not more than three layers, the amount of Ga contained in the particle size-adjusted powder is in a range from 0.10 to 1.0% with respect to the sintered R-T-B based magnet work by mass ratio.

The present invention provides a downhole heating tool with an increased heating capacity for use in setting alloy plugs/seal in downhole target regions of wellbores, such as oil/gas wells. The increased heating capacity enables greater quantities of alloy to be melted in one operation. It also enables alloys with higher melting points to be melted in the downhole environment. To this end the heating tool comprises a plurality of discrete tubular heating units linked together by connection means that permit the movement of the tubular heating units relative to one another. The relative freedom of movement between the heating units facilitates a transition between a deployment configuration, in which the heating tool is optimised for deployment downhole, and a heating configuration, in which the heating tool adopts an expanded heating footprint within a downhole target region.

The present invention provides a downhole heating tool with an increased heating capacity for use in setting alloy plugs/seal in downhole target regions of wellbores, such as oil/gas wells. The increased heating capacity enables greater quantities of alloy to be melted in one operation. It also enables alloys with higher melting points to be melted in the downhole environment. To this end the heating tool comprises a plurality of discrete tubular heating units linked together by connection means that permit the movement of the tubular heating units relative to one another. The relative freedom of movement between the heating units facilitates a transition between a deployment configuration, in which the heating tool is optimised for deployment downhole, and a heating configuration, in which the heating tool adopts an expanded heating footprint within a downhole target region.

The present invention provides a magnet structure comprising a first magnet, a second magnet, and an intermediate layer joining the first magnet and the second magnet. In the magnet structure, each of the first magnet and the second magnet is a permanent magnet comprising a rare earth element R, a transition metal element T, and boron B. In addition, the rare earth element R comprises: a light rare earth element R.sub.L comprising at least Nd; and a heavy rare earth element R.sub.H, and the transition metal element T comprises Fe, Co, and Cu. Further, the intermediate layer comprises: an R.sub.L oxide phase comprising an oxide of the light rare earth element R.sub.L; and an R.sub.L—Co—Cu phase comprising the light rare element R.sub.L, Co, and Cu.

The present invention provides a magnet structure comprising a first magnet, a second magnet, and an intermediate layer joining the first magnet and the second magnet. In the magnet structure, each of the first magnet and the second magnet is a permanent magnet comprising a rare earth element R, a transition metal element T, and boron B. In addition, the rare earth element R comprises: a light rare earth element R.sub.L comprising at least Nd; and a heavy rare earth element R.sub.H, and the transition metal element T comprises Fe, Co, and Cu. Further, the intermediate layer comprises: an R.sub.L oxide phase comprising an oxide of the light rare earth element R.sub.L; and an R.sub.L—Co—Cu phase comprising the light rare element R.sub.L, Co, and Cu.

Provided is a thermoelectric conversion element having a high Anomalous Nernst Effect at a lower cost. A thermoelectric conversion element (1) includes a magnetic alloy material containing aluminum, cobalt, and samarium, and a power generation layer (10), in which in the power generation layer (10), a content of aluminum in the magnetic alloy material is in a range of 1 atomic percent to 40 atomic percent, a content of samarium in the magnetic alloy material is in a range of 12 atomic percent to 40 atomic percent, and a content of cobalt in the magnetic alloy material is in a range of 57 atomic percent to 82 atomic percent.

Provided is a thermoelectric conversion element having a high Anomalous Nernst Effect at a lower cost. A thermoelectric conversion element (1) includes a magnetic alloy material containing aluminum, cobalt, and samarium, and a power generation layer (10), in which in the power generation layer (10), a content of aluminum in the magnetic alloy material is in a range of 1 atomic percent to 40 atomic percent, a content of samarium in the magnetic alloy material is in a range of 12 atomic percent to 40 atomic percent, and a content of cobalt in the magnetic alloy material is in a range of 57 atomic percent to 82 atomic percent.

Provided is a silicide-based alloy material with which environmental load can be reduced and high thermoelectric conversion performance can be obtained.

Provided is a silicide-based alloy material including silicon and ruthenium as main components, in which when the contents of silicon and ruthenium are denoted by Si and Ru, respectively, the atomic ratio of the devices constituting the alloy material satisfies the following:

45 atm %≤Si/(Ru+Si)≤70 atm %

30 atm %≤Ru/(Ru+Si)≤55 atm %.

Provided is a silicide-based alloy material with which environmental load can be reduced and high thermoelectric conversion performance can be obtained.

Provided is a silicide-based alloy material including silicon and ruthenium as main components, in which when the contents of silicon and ruthenium are denoted by Si and Ru, respectively, the atomic ratio of the devices constituting the alloy material satisfies the following:

45 atm %≤Si/(Ru+Si)≤70 atm %

30 atm %≤Ru/(Ru+Si)≤55 atm %.